Computer Terms A-E

FULL IT GLOSSARY

•     32-bit/16-bit: There are many advantages that 32 bit has over the 16 bit applications. 32 bit application have their own address space which creates a stable environment for a computer system. Whereas the 16 bit version runs in a shared address space which means if you experience a 16 bit application crash, it can crash the entire system. In addition, 32 bit runs much faster, it can handle multitasking and can handle much longer filenames than can the 16 bit application.

•     Absolute Address:

The exact memory location of data or a specific location within a device.

•     Absolute Reference: A formulated cell reference that will not adjust when used to calculate the sum of specific cells. Most commonly used in spreadsheet applications.

•     Access Point: A networking connection device that is also known as the base station. This is a wireless hardware connection device that connects to a wired network to create wireless operation. Its point of access is a local area network (LAN).

•     AI: Stands for Artificial Intelligence. This is the area of computer science focusing on creating machines that can engage on behaviors that humans consider intelligent. The ability to create intelligent machines has intrigued humans since ancient times, and today with the advent of the computer and 50 years of research into AI programming techniques, the dream of smart machines is becoming a reality. Researchers are creating systems which can mimic human thought, understand speech, beat the best human chess player, and countless other feats never before possible.

•     ACPI: Advanced Configuration and Power Interface. This interface was first introduced in 1996 and was developed to control computer devices power distribution. For example, if a device was currently not in use, the ACPI would turn this device off to create more power where necessary for smoother operation.

•     Active Matrix: A type of LCD (liquid crystal display) structure that is actively controlled by a diode or transistor. This allows for each pixel to be independently controlled which produces excellent color resolution.

•     Active X: A software technology developed by Microsoft. This is based on other technology Microsoft developed such as; COM (Component Object Model) and OLE (Object Linking and Embedding). Active X defines how applications share information. While Active X gives much more freedom as to how certain applications are viewed, it has inherent security risks.

•     Actuator:

Device that performs an action or outputs a signal in response to a signal from a computer.

•     Addressing: A method of identifying a resource (such as a program) or piece of information (such as a file) on a network. Methods of addressing vary considerably from network-to-network.

•     Adware: A software program that is designed to run once a web page has been accessed. This is usually in the form of banner or popup advertisements. Adware can also be designed to be installed on your system without your consent or knowledge. These forms of adware are usually referred to as “spyware” and are used to monitor your surfing habits so that their software can deliver better targeted advertisements. In other instances, the software can be designed to monitor your keyboard keystrokes so that the author of the software can gain access to your password protected accounts. This type of adware is referred to as “malware” due to its malicious intent.

•     Aero: Aero is the name of Windows Vista’s new graphical interface that gives users an exciting new desktop look and feel. It stands for: Authentic, Energetic, Reflective and Open. It is designed to be very aesthetically pleasing. It’s effects include:

-Glass effects

-Advanced Window Management features -Desktop Composition which creates a more stable experience

•     AGP: Stands for Accelerated Graphics Port. This interface specification was developed by Intel Corporation. It was designed to give lower costing graphics cards much faster access to the main memory on personal computers.

•     AGTL Signaling: (Assisted Gunning Transistor Logic) AGTL and AGTL+ use the same signaling protocol only at different voltage levels. AGTL+ operates at 1.5V signaling levels, while AGTL operates at 1.25V.

•     Algorithm: A formal set of instructions that can be followed to perform a specific task, such as a mathematical formula or a set of instructions in a computer program.

•     Alias: A shortcut or ‘friendly name’ that points to a file folder or application. As an example, when you enter in a user name for an application, this user name would be an ‘alias’.

•     Aliasing: This refers to the distortion in a sound or image generation. A sound distortion occurs when digitally recording high frequencies with a low sample rate. An image distortion occurs when a printer, monitor or graphic file has an insufficient amount of resolution to display an image properly.

•     AMD: (Advanced Microchip Devices) A semiconductor manufacturer and is a major competitor of Intel. They manufacture the Athlon, Duron, and K6 CPU chips.

•     Analog: Anything whose behavior corresponds with the behavior of something else, especially if the correspondence varies continuously rather than in steps. For example, the height of the liquid in a thermometer is an analog of the temperature. The signals that go from a computer to a composite monitor are analog voltages.

•     AppleTalk: A protocol suite developed by Apple Computer in the early 1980s, was developed in conjunction with the Macintosh computer. AppleTalk’s purpose was to allow multiple users to share resources, such as files and printers. The devices that supply these resources are called servers, while the devices that make use of these resources (such as a user’s Macintosh computer) are referred to as clients. Hence, AppleTalk is one of the early implementations of a distributed client/server networking system.

•     AppleScript: It is a kind of English-like language that is used to write specific script files which have the ability to automate the actions of the computer systems and applications that run on it.

•     AppleShare:

This is Apple’s network system. It is to the Macintosh what FTP is to the PC.

•     Applet: An applet is a small program generally written in the Java programming language that was designed to provide interactivity on web pages.

•     Application: An application is a program that is designed to perform specific tasks. A few examples of some popular applications are:

-Microsoft Windows -Microsoft Word -Adobe Photoshop -Internet Explorer

•     Application Server: This is a specialized server based in a client/server network that has the sole responsibility of running specific applications within that network.

•     Archie:

Or ArchiePlex which is an Archie gateway for the World Wide Web. It can locate files on Anonymous FTP sites

in the Internet.

•     Archive:

This usually defines old files that are no longer in use and are stored for possible future use or reference.

•     Arithmetic Logic Unit (ALU): Arithmetic Logic Unit. This is a mathematical core circuitry that applies to all computers central processing units (CPU). ALU mathematically and logically calculates the results of binary data.

•     ASCII: It stands for “American Standard Code Information Exchange” and is pronounced (ask-ee). A standard code or protocol for displaying characters and transferring data between computers and associated equipment. It was developed for the purpose of information exchange among the following:

-Associated equipment -Data communications systems -Data processing systems

There are 128 standard ASCII codes each of which can be represented by a 7 digit binary number: 0000000 through 1111111.

•     Asynchronous:

1 : not synchronous; not occurring or existing at the same time or having the same period or phase.

2 : of, used in, or being digital communication (as between computers) in which there is no timing requirement for transmission and in which the start of each character is individually signaled by the transmitting device.

•     ASP: In computing, this stands for “Active Server Pages”. Developed by Microsoft and is designed as a web server extension which is a default scripting language for writing VBScript.

•     ATA: Short for “Advanced Technology Attachment”, this is a disk drive implementation developed by the Small Form Factor (SFF) Committee that integrates the controller on the disk drive itself. There are many versions of ATA, which include:

-ATA: Also known as as IDE, supports one or two hard drives, a 16-bit interface and PIO modes 0, 1 and 2. -ATA-2: Supports faster PIO modes (3 and 4) and multiword DMA modes (1 and 2). Also supports logical block addressing (LBA) and block transfers. ATA-2 is marketed as Fast ATA and Enhanced IDE (EIDE). -ATA-3: Minor revision to ATA-2. -Ultra-ATA: Also called Ultra-DMA, ATA-33, and DMA-33, supports multiword DMA mode 3 running at 33 MBps. -ATA/66: A version of ATA proposed by Quantum Corporation, and supported by Intel, that doubles ATA’s throughput to 66 MBps. -ATA/100: An updated version of ATA/66 that increases data transfer rates to 100 MBps.

•     ATM: “Asynchronous Transfer Mode”. This is an International standard for cell relay where multiple service types (such as data, video or voice) are communicated in cells that are of a fixed length (53-byte).

•     ATX: This doesn’t stand for anything that I could find. It is a very popular specification for motherboards in computing. It was designed to take the older AT motherboards, often referred to as “Baby AT” (an earlier standard) and rotating it 90 degrees to allow for more available space for add-in cards.

•     autoexec.bat:

A root directory batch file that is responsible for executing commands at system startup.

•     AVI: Stands for “Audio/Video Interleaved”. To date, AVI is the most common format for audio/video data on the personal computer.

•     Backbone: This computer term describes the main line or series of connections in a network. The backbones are connection points where high-speed data on the Internet connects to networks.

• Backup: To copy files to a second source or media in an effort to safeguard the original version. When computer, the first rule is to backup your files regularly. Even if you think you have the most reliable of computers, you just never

know when its time is up. It is recommended that you keep your backup copy in a separate place from the original.

• Bandwidth: A measurement of how much data that can be sent through a connection. The measurement is usually in bits per second.

• Baseband: A method of transmission that sends a digital or analog signal in its original form, not changed by modulation. While this form of transmission can be much more reliable than its Broadband counterpart, it is much slower.

• Batch File: A file that has the .BAT extension. This file usually contains a sequence (or batch) of commands. A batch files set of commands can be executed all at once by the batch file name rather than by each individual command name.

• Baud: Pronounced bawd>. This term is named after J.M.E. Baudot who invented of the Baudot telegraph code. Commonly, the baud rate of a modem is how many bits it can send or receive per second. Technically, baud refers to the number of times per second that the carrier signal shifts value. As an example, a 1500 bit-per­second modem actually runs at 375 baud, but it moves 4 bits per baud (4 x 375= 1500 bits per second).
• • BBS: Stands for Bulletin Board Service. A program designed to bring people together where they can carry on discussions and download files where all of the other members of the service can monitor these transmissions in real time.
• • Beta: A testing stage for products (both hardware and software) that are being developed. It is referred to as the “beta version”.
• BIOS: Stands for Basic Input/Output System. The BIOS gives the computer a little built-in starter kit to run the rest of softwares from floppy disks (FDD) and hard disks (HDD). The BIOS is responsible for booting the computer by providing a basic set of instructions.
• Binary: A basic numbering system that consists of ones and zeros.
• Bit: (Binary DigIT) This refers to a single digit number. It is either a 1 or a zero. The binary digit is the smallest unit of computerized data.

• Bit Depth: Bit Depth can be referred to as Color Depth or Pixel Depth. It refers to a method of measurement where using the number of bits to define each pixel in an image to determine its color range. The larger the Bit Depth, the larger number of tones (grey scale or color) are available to properly display the digital image.

• Bitmap: A file format used for digital imagery. This format maps an image pixel (or bit). All computer systems use this file format. Some of the common types of bitmap file formats would be:

• BMP
• GIF
• JPEG
• PCX
• PNG
• TGA
• TIFF

• Blog: (Slang term for a Weblog) A blog is a person journal that can be accessed publicly and allow people to comment on the previously posted comments. When someone posts a comment to a blog this is called “blogging”. The person that owns the blog is called a “blogger”. Most typically, blogs are updated on a daily basis and use the most basic of formats so that a person with very little background in computing can easily figure out how the blogging system works.

• Blu-ray: Also known as Blu-ray Disc. This is an optical disc format that was developed to enable recording, playback, and rewriting of high-definition (HD) video. This technology has a storage capacity far greater than that of traditional DVDs. A single-layer disc can hold up to 25GB while a dual-layer disc can hold up to 50GB. DVD disc technologies use a red laser to read and write data. Blu-ray uses a blue-violet laser (hence the name). The benefit of the blue-violet laser over the red laser is its ability to focus the laser spot with greater precision because of its shorter wavelength. A red laser’s wavelength is 650nm while the Blu-ray’s wavelength is 405nm.

• Bluetooth: Radio technology that connects electronic devices without using a cable. Data and voice can be exchanged at ranges of up to 10 meters without the need for devices to be lined up together.
• BMP: (pronounced “bimp”): It is a Microsoft Windows image file format known as bitmap.

• BNC: In computing, a Bayonet Network Connector is commonly used in the CCTV industry, usually installs on coaxial cable. The benefit of this connector is its ease of installation and its ability to produce a very reliable video signal.

• Boolean Logic: A type of mathematical logic named after its designer George Boole. This binary algebraic system is used primarily in switching circuits and database searches. Search engines use logical operators called, Boolean Operators (AND, OR, NOT).

• AND: Narrows a keyword search by collecting all terms present in the same document.
• NOT: Prevents retrieval of unwanted documents containing a keyword.
• OR: which broadens a keyword search by linking related terms.

• Boot Disk: This refers to a diskette that is formatted to actually boot your computer from. They were created as a backup tool in case the normal boot method (hard disk) has failed.

• Bridge: A bridge is a computer networking device used to make a connection and pass along packets of data between two networking computers using the same protocol.

• Browser: A browser is the software used for viewing pages on the web. Two examples are Microsoft Internet Explorer and Netscape Navigator.
• • Buffer: A place, especially in RAM, for the temporary storage of data for the purpose of speeding up an operation such as printing or disk access. Data from a buffer is available more quickly than data from where the buffer got it. Typically buffers get data before it is needed so it will be ready quickly when it is needed. Similar to cache.
• • Buffered Memory: Using a buffer to isolate the memory from the controller reduces the load on the chipset. This allows for more memory chips to be used.
• BUS: A bus is a grouping of wires that allow the flow of data from one area of the computer to another. It is thought of that a bus represents a highway that the data travels through in the computer system. In personal computing, some refer to a bus as the Internal bus which connects all of the devices to the CPU and memory. Also, you may hear the term expansion bus, which connects the expansion board with the CPU and memory.

All buses are made up of two parts:

• Data Bus
• Address Bus

The data bus is responsible for the actual data transfer whereas the address bus will route the data to the proper place.

The size of the bus, which is measured in width is the amount of data that it is able to transmit. For instance, a 16 bit bus will be able to transfer 16 bits of data and a 32 bit bus can transfer 32 bits a data.

Another thing that all buses have in common is that they all have a clock speed. This clock speed is measured in MHz (megahertz). The faster the clock speed of the bus the faster the application will run. In older PC’s the bus that was used was the ISA bus. These older buses are quickly being replaced by the speedier PCI bus.

Most PC’s today require a speedy bus that can transfer data very rapidly. This is what a “local bus” will do. It is a high-speed information highway that connects directly to theprocessor.

Lastly, you may hear the term “bus” used in networking. This refers to cable that connects all of the internal devices on a local area network (LAN) also referred to as the “backbone”.

• Bus Mastering: A technique that allows certain advanced bus architectures to delegate control data transfers between the CPU and associated peripheral devices to an add-in board. This gives greater system bus access and higher data transfer rates than conventional systems.

• Byte: A byte is a computer data transfer or data storage measurement. One byte equals 8 bits.

• Cable Modem: A cable modem is a type of Internet connection that is transmitted through a coaxial cable. The benefits of this technology are that you are able to achieve much faster speeds through a cable connection and that most homes are already setup with a cable TV setup, making the Internet connection very simple.

• Cache: A very high speed type of memory that is similar to random access memory (RAM). The difference in RAM and Cache is that the Cache memory is on the server side and the RAM is stored in the computer system. Cache is much faster than RAM but they both serve the same purpose and that is to remember previously accessed information. Most commonly, the Cache memory is to remember the previously visited web page so that the computer itself doesn’t have to spend its resources providing the page.

• Cache RAM: Cache (commonly referred to as SRAM) is responsible for storing frequently requested instructions and data. It is a small block of high-speed memory located between the CPU and the main memory. When your computer processor needs data, it will check the Cache first to see if it is there. If the data is not there, it will retrieve it from the slower main memory.

• CADD (Computer Assisted Design and Drafting): A graphics software designed to assist users develop on-screen projects, usually rendering in either 2 or 3 dimensional imagery.

• Cascade: A method of connecting circuits together in series to make the output of one, the input of the next. This kind of end-to-end connectivity is useful in extending the distance of a network.

• CATV: Community Antenna Television or Cable TV system. Can be all coaxial or HFC (Hybrid Fiber Coax) based.
• CD-ROM: (Compact Disc Read-Only Memory) A durable and low cost circular optical storage device widely used to store large amounts of information on a personal computer.
• Centronics:

A 36-pin parallel port interface standard that most printer manufactures conform to.

• CGA: Stands for Color Graphics Adapter. Introduced by IBM as their first microcomputer color standard. This graphics card allowed a maximum of four colors at a resolution of 320 x 200 or two colors at 640 x 200.
• CGI: The “Common Gateway Interface”. CGI provides a gateway for HTML pages to interact with other applications.
• Channel: A channel in computing is a specific bandwidth and frequency combination.

• Chassis: The physical framework of a computer system that houses all of the internal devices, wiring, and power supplies.

• CICS: “Customer Information Control System”. A general purpose IBM mainframe-based transaction management system. CICS is one of IBM’s most widely used database / data communications subsystems.

• Client: A client is commonly referred to as a program or a process that requests information from other programs or processes. A web browser is a good example of a client. Another example would be an email client such as Outlook Express.
• Clipboard:

A temporary data (text and graphics) storage facility used when transferring data to a new location.

• Clock Speed: The clock speed is the frequency which determines how fast devices that are connected to the system bus operate. The speed is measured in millions of cycles per second (MHz or megahertz) and is generated by a quartz crystal on the motherboard which acts as a kind of metronome. Devices that are synchronized with the clock may run faster or slower but their speed is determined by multiplying or dividing a factor by the clock speed.

• Clone: An imitation or copy of the original. Usually refers to building a computer system that is based on and compatible with another computer company’s system.

• Cluster: In a Windows environment, Cluster refers to the allocated space within files measured in units. A cluster is part of a group of a logical disk sector. Depending on the disk size, a typical cluster size can range from 1 to 64 sectors.

Cluster can also refer to a group of computers networked together and used as a single unit.

• Clustering: This is a way of connecting two (or more) computers together using clustering hardware so that they share the processing load. If ten computers of equal processing speed are clustered together, you would in a sense have a single computer with ten times the processing capacity. The most common use of this technique is with search engines where it is used to provide speedy search results. A couple of other common uses of clustering can be to increase storage capacities or for networks that require load balancing to increase a networks availability and stability.

• CMOS: Most commonly, CMOS refers to a battery powered chip that resides on the Motherboard and is responsible for retaining certain system information (date, time and some system setup parameters) when the computer system is turned off.

• CMTS: Cable Modem Termination System. Typically, this system is found in a cable companies headend or distribution hub. Its purpose is to provide a high-speed data service to cable subscribers.
• COBOL: Stands for Common Business Oriented Language. A computer programming language invented during the second generation of computers and designed to meet the needs of business. Although less often used today, it was well-suited for writing programs that process large files and generate reports.
• • Codec:

.       Short for Compressor/Decompressor. This technology is used for compressing and decompressing data. Codecs are widely used in both hardware and software. A few examples of codecs are: Cinepak, Indeo and MPEG.

.       Also stands for Coder/Decoder in the telecommunications field. This is a device that encodes or decodes a signal. A common use for this device would be in telephone companies digital and analog networks. It is used to convert binary signals to analog signals.

.       The transformation of a binary value into a voltage that can be transmitted over a wire.

• Cold Boot: A cold reboot also referred to as a hard boot. This occurs when a computer user must switch the computer system off from the main power switch. This process bypasses the normal shut down procedure of the operating system. A cold boot can also be the result of a power failure but is usually performed by the user as a last resort because of either a system failure or a “hung” state.

• Collision: This is a problem that is a result from two or more device attempting to send a signal along the same channel. The usual result of a collision is a garbled message. All computer networks have in place some sort of mechanism to either prevent collisions altogether or to quickly recover from a collision if they were to occur.
• • COM: Stands for Component Object Module. This is a Microsoft standard created to allow for the communication of computer components (or objects) on the same computer system. This specification is very useful because of its ability to integrate many distributed application services in one package.
• • Command Line: Commands you type to run an application. You can type commands at an MS-DOS prompt or in the Run dialog box in the Program Manager of Windows. Interfaces in which you type commands rather than choose them from a menu are often called command line interfaces. MS-DOS has a command line interface while the Macintosh does not.
• • Compiler: This is an application that converts a programming language into a machine language program.
• • Compression: This refers to the reduction of a file size. This technology is very helpful in saving time and space. Example: When e-mailing a large document, using a compression software to reduce the file size will allow the file to be sent and received much faster.
• Config.SYS: The configuration file for DOS systems. Each time a DOS computer boots up, it reads from the CONFIG.SYS file (if present) and will execute any prewritten commands. A couple of the most common file held within the Config.sys are: BUFFERS= and FILES=. These commands enable the system to specify the buffer size and the number of files that are allowed to open at once. Commands can also be held in the Config.sys that will install device drivers.

• Constraint: A data rule that limits a searches possibilities through preset algorithms. The constraint could include an algorithm that would rule out certain data relationships allowing the search to proceed much more quickly.

• Contrast Ratio: This is a dynamic range measurement method. It measures the contrast ratio as it applies to images and text. Detailed images have a higher contrast ratio.

• Controller: A controller is a device responsible for transferring data from a computer system to peripheral device or in reverse. Each device within a computer system has a dedicated controller. The controllers for a monitor and keyboard are included when you purchase a computer system. If you were to add additional devices, you may be faced with purchasing additional controllers for these new devices. Care must be taken that the proper controller is purchased that can communicate with the systems expansion bus.
• Conventional Memory: In a DOS environment, this would refer to a memory portion that is made available to DOS programs. In a typical DOS system, there is 1MB (megabyte) of address space available. Conventional Memory is allotted 640K of the address space. The other 384K of memory is used by the system and is called “high memory”. Any memory beyond the 1MB is expanded memory.

• CPE: This refers to ports or other equipment supplied by the manufacture so that the end user can connect to a network. A typically supplied CPE is either a switch or a router.

• CPM:

(Cost Per Thousand) This is a calculation method involving 1000 advertisement impression displays. The CPM rate of pay is calculated based upon these 1000 impressions. One scenario might be that a person would agree to pay you ten dollars for each time the advertisement displays on your web page or site one thousand times.

• CPU: Central Processing Unit. In a microcomputer, a processor on an IC chip (called a microprocessor) that serves as the heart of the computer. It interprets and carries out instructions, performs numeric computations, and controls the peripherals connected to it. Often the entire system unit is called the CPU.

• Critical Mass: The scale or volume at which processes become self-perpetuating. In Web publishing, it is said that after achieving a certain amount of material and resources, it will create a self-sustaining chain reaction.

• CSS: Stands for Cascading Style Sheets. This is a language designed to work with HTML documents on the Web. CSS is generally used to provide a specific appearance or style to a web page or site. A common use for CSS could be that it is written to specify the links rollover color in a web sites navigation structure. CSS is becoming much more widely used by webmasters due to the file size benefit of using style sheets.

• Cursor: A cursor is a blinking indicator designed to mark the place of text where a person may be working within a document.

• Cyberspace: Author William Gibson in his novel Neuromancer describes a more highly developed form of the Internet and who originally coined the term Cyberspace. The word Cyberspace is currently used to describe the whole range of information resources available through computer networks.
• Cyberpunk: The term Cyberpunk could be used to describe an individual that hacks their way in to computer system with the intent of stealing or destroying the information in the system. It term was actually originated by a science fiction writer that described a lawless futuristic society dominated by computer technology.

• Daemon: This refers to a program that is designed to run continuously in the background and is activated by a particular event. Examples of Daemons are: mail server daemons, web server daemons or printer daemons.

• Daisy Chain: A hardware configuration in which devices are connected one to another in a series. The SCSI interface , for example, supports a daisy chain of up to 7 devices.

• Data:

This refers to the information that is stored on a computer system.

• Database: Anything that accepts data is a database. A pile of newspapers is a database. A computer database has the ability to manipulate that data. It is possible to attach applications to that database to search the contents.

• Data Bus: Data Buses are used on a systems motherboard and contain a group of parallel conductors also known as circuit traces. Data Buses are used by the CPU to transmit and receive data from all connected devices in a computer system. It is also referred to as the external data bus.

• Data Communications:

The moving or sharing of encoded information between two or more data sources using an electronic medium.

• Data Conversion: Refers to translating data from one format to another. It is most commonly used to reformat data that is being transferred from one system to another so that the receiving system can interpret the information correctly.

• Data mining:

Sorting through data to identify patterns and establish relationships. Data mining parameters include:

-Association – looking for patterns where one event is connected to another event. -Sequence or path analysis – looking for patterns where one event leads to another later event. -Classification – looking for new patterns (May result in a change in the way the data is organized but that’s ok).

-Clustering – finding and visually documenting groups of facts not previously known. -Forecasting – discovering patterns in data that can lead to reasonable predictions about the future.

• Data Rate: A speed measurement that calculates how fast information is moved from one place to another. This is usually measured in bits.

• Data Striping: A method of separating data from one disk drive and distributing it across several hard disks. The benefits of Data Striping are:

-When a processor is capable of reading or writing faster than a single disk drive can accept the information. Data Striping will increase the I/O performance. -Gives the ability to create larger logical volumes. -Reduces the possibility of disk drive failure.

• Daughter Card: Often called Daughter Board. it is a printed circuit board that plugs into another circuit board (usually the motherboard). A daughter card is similar to an expansion board, but it accesses the motherboard components (memory and CPU) directly instead of sending data through the slower expansion bus. It is different from other expansion boards in the system due to it often having pins, plugs, sockets or connectors.

• DDR: Stands for “Double Data Rate.” A type of advanced SDRAM designed to deliver data at a double rate of speed for a given clock frequency. DDR is used in some of the newer video cards such as Nvidia GeForce.

• DDS: Stands for Direct Digital Signal. It refers to a network that uses digital infrastructure equipment exclusively. This eliminates the need for analog-to-digital converters on a network because all signals are transmitted digitally.

• DECnet: A proprietary set of networking protocols developed by the Digital Equipment Corporation. It was the first peer­to-peer networking architectures to emerge in the 1980’s.

• Decoder: A software, hardware or circuit that is designed to translate a coded or scrambled signal in to a readable form. A common use for this is by cable companies that scramble a signal until a subscriber becomes authorized to view the signal. The cable company then decodes the signal in to a viewable form.

• Decryption: This is a process of converting information in to a readable form that has been encrypted by the use of an encryption algorithm. A common use could be that a person would like to protect sensitive data that resides on their computer system, so they would use an encryption software to scramble the information. The same software that scrambles the information would be the only authorized entity to decrypt the information. This software could be made available to any authorized person for decryption purposes at other locations.

• Dedicated Line: This refers to a phone line that is a phone line that is connected for one purpose. Many computer users use a dedicated line specifically for their computer system.

• Degauss: To remove magnetism from a device. The term is usually used in reference to color monitors and other display devices that use a Cathode Ray Tube (CRT). These devices aim electrons onto the display screen by creating magnetic fields inside the CRT. External magnetic forces — such as the earth’s natural magnetism or a magnet placed close to the monitor — can magnetize the shadow mask, causing distorted images and colors. To remove this external magnetic forces, most monitors automatically degauss the CRT whenever you turn on the monitor.

In addition, many monitors have a manual degauss button that performs a more thorough degaussing of the CRT. You can also use an external degausser that degausses the monitor from the outside. Since it may be impossible to remove the external magnetic force, degaussing works by re-aligning the magnetic fields inside the CRT to compensate for the external magnetism.

• Delimiter: A text character that marks the beginning and/or end of a unit of data or separates different data components. For example, periods are used as delimiters in domain names, hyphens and parentheses are used in phone numbers and social security numbers, and blank spaces and commas are used in written text. In HTML the opening delimiter of an element or tag is the less than symbol, <, and the closing delimiter is greater than symbol, >.

• Demodulation: This is a process used by some phone companies that convert an analog signal in to digital signal for use by computer systems.

• Desktop: Once an operating system finishes loading and you are able to see the graphical background and program icons, this is said to be your “desktop”. The electronic desktop is a metaphor for the actual desktop at your home or office in which you will find your many business tools.

• Desktop Window Manager (DWM): This new visual style (Aero Glass) and look in Windows Vista is powered by Windows Vista’s Desktop Window Manager. A video card supporting the Longhorn Display Driver Model (LDDM) system is necessary to view Aero Glass.

• DHCP: Dynamic Host Configuration Protocol. This is a process of dynamically allocating IP addresses so that they can be reused. This provides a way of managing IP addresses for all PC’s connected to cable modems in a network.

• DHTML: Stands for Dynamic HTML. This term applies to many web design standards such as HTML, JavaScript and CSS where these elements may be intermixed to create more dynamic design elements. By using DHTML, users can have the ability to drag or click preset design features of a web page.

• Dial-Up Line: This is a telephone line that is connected to a server. When it is called, tones are exchanged between the server and the devise calling in order to attach.

• Dial-Up Networking: This is a feature that was used by the Windows 95, 98 and Unix operating systems. It allows for the connection of other computer systems over the Internet using a phone line connected to a modem.

• Digital: A system that defines data in a discrete, non-fluctuating (i.e., non-analogue), numerical method. Similar to a binary system.

• Digital Light Processing (DLP): A video projection technology that uses hundreds of thousands of rotating mirrors to project high quality, high definition images. DLP was originally developed by Texas Instruments.

• DIMM: Short for Dual In-line Memory Module. DIMM is a later version of memory than that of its earlier SIMM (Single In-line) counterpart. A DIMM module was introduced for the Pentium processor because the Pentium processor needed a 64 bit path. The SIMM module only has a 32 bit path. Also, SIMM modules are required to be replaced in pair whereas the DIMM modules can be replaced one at a time.

• DIP:

Acronym for Dual In-line Package. This is a type of chip that was most popular when memory was directly

installed on the motherboard. It can be identified by its rectangular casing and has two rows of connector pins on both sides.

• Direct X: Developed by Microsoft for its Windows operating systems. This technology was designed to provide a much broader gaming or multimedia environment. In the later versions of DirectX, more attention to 3D graphics have been applied. It works by giving software developers direct access to low-level functions of a PC’s peripherals by providing a set of application programming interfaces (APIs).

• Directory: In computing, this refers to the separate entities of a file system. A directory can contain thousands of files and folders used as a means of adding or updating data and is usually an organized searchable reference.

• Distributed Network: A network using multiple locations. This process if very effective when a specific job can be dynamically tackled by each node in the network rather than by using one individual machines processor.

• DLL: Dynamic Link Library. This refers to a file that contains executable code that can be used by many different programs at the same time. DLLs have great benefits to a systemsstorage structure and offer performance benefits as well. Once a program is activated, the DLL file for that program is executed giving the system the proper instruction for that program. If another program uses the same set of instructions, the same DLL will will execute the same instructions for that program. Having the DLL files saves the system from storing this information in a dedicated manor which creates a faster load time for the program and saves a lot of space on a systems hard drive. Dynamic link libraries are stored in files with the .DLL file extension.

• DMA: (Direct Memory Access) This is a method of bypassing the central processing unit (CPU) and handling data transfers between the memory and peripheral devices. Systems having DMA channels can transfer data much more quickly than those without.

• DNS: Domain Name Service. This service changes alphabetical domain names in to IP (Internet protocol) addresses. While domain names, such as 5StarSupport are very easy to remember, the Internet is made up of IP addresses. Here’s how it works; a company or organization settles on a domain name to use. They then purchase the unique name from a DNS server. The organization then purchases a hosting package from an Internet hosting service. The organization can now upload all of their web site information to the host using a special code supplied by the DNS server.

• DOCSIS: Data Over Cable Service Interface Specification. This is a cable modem standard that was developed by CableLabs. It handles the incoming and outgoing data signals between cable TV networks, personal computers or television sets.

• Dongle: A device that attaches to a computer to control access to a particular application. Dongles provide the most effective means of copy protection. Typically, the dongle attaches to a PC’s parallel port. On Macintoshes, the dongle sometimes attaches to the ADB port. The dongle passes through all data coming through the port so it does not prevent the port from being used for other purposes. In fact, it’s possible to attach several dongles to the same port.

• DOS: Stands for Disc Operating System. This is a command line operating system that was created by Bill Gates while he was working for IBM. The Windows operating systems are designed to run on top of the DOS system. It is more commonly referred to as MS-DOS. The MS stands for Microsoft.

• Downstream: This term refers to any information that is being received by a computer system. If the information is leaving the computer system it is referred to as “upstream”.

• Downstream frequency:

Refers to the frequency that is used when transmitting information between the CMTS and cable modem.

• Domain: A domain is a computer, web site or network that is connected to the Internet. A typical domain name looks like this: www.5starsupport.com. The “www” prefix signifies that it is connected to the world wide web. The “5starsupport” or body usually indicates the company name and the suffix “com” is the indicates that it is a commercial site.

• Domain Name: This is a unique identifier of an organization attached to the Internet. Domain names are used to make a web site easier to remember rather than trying to remember a series of long numbers known as an IP (Internet Protocol) address.

• Dot Pitch: An image measurement taken from center to center between stripes or phosphor dots on monitor. The smaller the number, the better the image quality. This measurement is taken in millimeters and it is considered that 0.28 mm is the minimum acceptable display quality. The dot pitch of color monitors for personal computers ranges from about 0.15 mm to 0.30 mm. Other terms for dot pitch is phosphor pitch or line pitch.

• DPI: Stands for Dots Per Inch. An image measurement standard that measures an images resolution as it applies to printers. It measures the images pixels in one square inch. The higher the number the better the images resolution or quality. A typical laser jet printers produce a resolution of about 300dpi. Photo quality inkjet printers produce a resolution ranging from 1200 to 2400 dpi.

• DRAM: Dynamic Random Access Memory. This is a common type of random access memory that is used in personal computing. The “dynamic” in its name is due to the fact that this memory needs to be refreshed as opposed to other SRAM that is “static”. The DRAM is refreshed by the use of electrical current pulses that pass through all memory cells. DRAM needs to be periodically refreshed to retain the stored data.

• Drive Bay: An allocated space inside a computer case where an internal device such as a; floppy, CD-ROM or DVD-ROM is mounted.

• Driver: A driver is a software program that is the driving force behind a device. Each computer device needs a driver. Many drivers are included with a computers operating system when you purchase it such as; keyboard, monitor and disk drives. In a Windows operating system, the divers file extension is .DRV. In a DOS system, they are .SYS. The driver is written with specific commands for the device it is written for.

• DSP: Digital Signal Processor. DSP is a technology that is commonly used in devices such as sound cards, fax machines, cellular phones, modems, high-capacity hard disk drives and televisions. DSP chips process large amounts of digital information very quickly. Because of its quick processing abilities, this technology continues to grow fast to meet the needs of today’s wireless and multimedia markets.

• DTP: Desk Top Publisher (ing) – A PC Term that describes a program that enables you to design, create and print a variety of projects such as letterheads, birthday cards, calendars, business cards, invitations etc. that would have previously only been possible by using the services of an outside printers business.

• Dual Core: This refers to a new Central Processing Unit (CPU) structure. The difference between a single core and dual core is that a dual core system has two CPU’s that are electronically wired together. These two CPU’s wired together in parallel gives twice the performance than that of its single core counterpart.

• Dumb Terminal:

This refers to a monitor a keyboard setup that can receive, enter, transmit and display information from a server.

But it cannot process any information. Most commonly, these terminals were used to communicate with another computer over a network. Dumb terminals are a thing of the past due to today’s availability of cheap computers.

• Duplex: This refers to a communication channel that has the ability to transmit in both directions. This is widely used in printing as you can print on both sides of the paper at once. Sometimes referred to as Full Duplex.

• DVD: Digital Versatile Disc or Digital Video Disc. This popular technology was first introduced in 1996. Its ability to store large amounts of information reliably made this a very common optical disc storage technology. It can hold between 4 to 28 times more data than that of the CD. A single sided DVD can store 4.7 GB (gigabytes) of information and 8.5 GB on dual-layered discs. Double sided DVDs can handle 9.4 GB on a single layered disc and 17 GB on a dual layered disc.

• Dynamic Programming Language:

This dynamic programming language has the ability to change the program structure as it runs.

• Dynamic URL: A Web site that is database driven can produce dynamic URLs. Or a URL of a Web site that is produced by running a script can be considered to be a dynamic URL. For instance, if you visit a Web page that displays a message that states: “This page has moved, you will be automatically be taken to the new page”. The Webmaster has written a script in to the old Web page that gives the ability to dynamically redirect you to the new page.

• E3: Similar to the North America T3 high speed digital transmission, the E3 European counterpart is capable of transmitting data at 34.368 Mbps.

• EBCDIC: Extended Binary Coded Decimal Interchange Code. It is also called the Extended ASCII Code. This is a common asynchronous code used by IBM. It is pronounced “ehb-suh-dik”. Many corporation that have legacy applications and databases in IBM’s OS/390 operating system use this code for the text files. The 8 bit character code is used to represent 256 different bit patterns.

• ECC Memory: Error Checking and Correction. A method of detecting and correcting system memory errors by adding additional bits and using a special algorithm.

• EDM (Electronic Document Management): Using specific document management software, users can capture and retrieve documents in image, audio, video and text forms.

• EDO Memory: Short for Extended Data Output, a type of dynamic random access memory. EDO memory is much faster than DRAM because it can access more than one block of information at a time. EDO memory accesses a block of memory and as it is sending the information from one block it starts accessing another block to fetch information.

• EEPROM: Electrical Erasable Programmable Read Only Memory. This type of memory can be reprogrammed and erased electronically repeatedly by using a device programmer which provides an electric surge. This memory is similar to DRAM, however not as fast, but EEPROM will retain its data even in the event of a power loss. Because of its similarities to flash memory, EEPROM is sometimes referred to as “Flash EEPROM”. The difference between flash memory and EEPROM is that EEPROM erases and rewrite data one byte at a time whereas flash memory has the ability to erase and rewrite in blocks. Therefore flash memory is much faster.

• EIDE: Enhanced Integrated Development Environment. This an enhanced version of the IDE hardware technology but is much faster. It allows for more memory, can access larger hard drives and can support up to four other IDE devices.

• E-Mail: Stands for Electronic Mail. This is a system of relaying messages across the Internet, from one Internet user to another.

• Embed: When adding an element from one document to another document. Example: A sound file is created in one document, then it is embedded in an HTML document for publication to the Web.

• Emulation: This term refers to a program or device that has the ability to imitate another. A common example would be that many printer manufactures software emulate the Hewlett-Packard Laser Jet software because of the fact that so many of these printers exist. Emulation does not exist only for software. Hardware can be emulated as well.

• Encryption: Encryption is the process of converting data into “unreadable code” is so that unauthorized people cannot understand the content. Encryption may be used to make stored data private (e.g., data that is stored on a potentially vulnerable hard disk), or to allow a nonsecure communications channel to serve as a private communications channel. Encryption is sometimes described as the process of converting plaintext into ciphertext. To decipher the message, the receiver of the encrypted data must have the proper decryption key.

• Engine: (as in “Search Engine”):

This is the working part of a database or application.

• Enhanced IDE: This is an enhanced version of the ATA-2 standard for managing the interface between secondary storage devices and a computer system.

• Environment: The interaction of all things external to a physical platform. This could be made up of software, hardware or networking procedures that communicate with the system to provide a particular service.

• EPROM: Erasable Programmable Read-Only Memory. It is pronounced “ee-prom”. This type of memory is designed to hold information until exposed to ultraviolet light in which case the information or memory is erased. Once exposed to this ultraviolet light, the EPROM can then be reprogrammed. A PROM burner or PROM programmer is used for the rewriting task. The difference between EPROM and its PROM counterpart is that the EPROM can be rewritten and PROM cannot. This makes it possible for the manufacture to change the contents of the EPROM to a newer or bug-free version prior to the computer being shipped.

• Error Rate: In many cases, it may be acceptable if an input device generates a certain number of errors. This is often referred to as the error rate and the acceptable level will vary according to the input device being used and the business application. Optical character recognition, for example, is generally considered a comparatively unreliable means of entering data. At present, a typical OCR software package will have an error rate of between five and ten per cent.

• ESD: Stands for Electro Static Discharge and is defined as a sudden flow of electricity between two objects at different electrical potentials. ESD is a primary cause of integrated circuit damage or failure.

• ESD Testing: Electro Static Discharge testing is one kind of test that hardware usually has to pass to prove it is suitable for sale and use. The hardware must still work after is has been subjected to some level of electrostatic discharge. Some organizations have their own ESD requirements which hardware must meet before it will be considered for purchase. Different countries have different legal regulations about levels of ESD.

• How to help prevent ESD: The best way to help prevent ESD is either to use a wrist strap, or a grounding mat. However most users do not have access to such items therefore you can follow the below guidelines to help prevent ESD as much as

possible.

• Clothes – Insure what you are not wearing an item that conducts a lot of Electrical Charge, such as a wool sweater. Also it is generally a good idea to remove all jewelry as well.
• Weather – When working on your computer insure there is not an electrical storm outside which increases the potential of ESD.
• Cords – Insure everything is removed from the back of the computer (power cord, mouse, keyboard, etc).
• Zero Potential – Insure you and the computer are at Zero Potential by continuously touching the un­painted metal chassis (computer frame) or the Power supply.
• Standing – When working inside the computer it is highly recommended that you stand at ALL times.
• Surface – It is always best to stand on a wooden surface. Avoid working on a computer in carpeted areas.

• Ethernet: A networking system that enables high speed data communication over coaxial cables. The Ethernet network system supports TCP/IP, AppleTalk, Novell Netware, and other network protocols. An Ethernet (LAN) connection is 10 Mbit/s or 100 Mbit/s, and is used to connect many computers that can all “talk” directly to each other. Normally they will all talk with a few servers and printers, but the network is all-to-all. The distance is normally limited to below 1 km.

• Executable File: An executable file or has a file extension of .EXE. It is a type of binary file designed to be directly executed by a computer system. Unlike source files, an executable file cannot be read by humans. They are specifically designed to be interpreted as a program.

• Expanded Memory: Anther term for Expanded Memory is EMS (Expanded Memory Specification). In a DOS based system there is 1 MB (megabyte) of address space available for main memory. 384K is for high-memory and 640K is for the conventional memory. To expand the memory capabilities, this technique is applied to the DOS system.

• Expansion Bus: A group of control lines that provide a buffered interface to devices located either on the system board or on cards that are plugged into expansion connectors. Common expansion buses included on the system board are USB, PC Card, and PCI.

• Expansion Card: This is a circuit card that it attached to the motherboards expansion slot. By using an expansion card, you can increase a systems functionality by providing the access to additional devices or features.

• Extended Memory:

This memory expands upon a DOS systems existing conventional memory.

• External Modem: A modem that is separate from the actual computer system and is self-contained in its own box. Because of the additional expense of creating the housing for the external modem, they tend to be a little more expensive that its internal modem counterpart. An external modem can be easily moved from one computer to the next because it is not attached directly to the printed circuit board is the internal modem is.

• Extranet: An extranet is similar to an intranet. They both use Internet protocols. The difference is that the extranet is designed to give a certain amount of access to outside users where an intranet is securely set behind a firewall and intended to be viewed by company employees or members of an organization only. An extranet can be controlled to provide various levels of accessibility to outside users and to what parts of the extranet they are authorized to view. See Also: Intranet