Computer Terms K-O

• K56Flex: A technology developed by Lucent Technologies and Rockwell International for delivering data rates up to 56 Kbps over plain old telephone service (POTS). It was long believed that the maximum data transmission rate over copper telephone wires was 33.6 Kbps, but K56flex achieves higher rates by taking advantage of the fact that most phone switching stations are connected by high-speed digital lines. K56flex bypasses the normal digital-to-analog conversion and sends the digital data over the telephone wires directly to your modem where it is decoded.

Lucent and Rockwell have announced that future K56flex modems will conform to the new V.90 standard approved by the ITU. And users with older K56flex modems may upgrade their modems to support V.90.

While K56flex offers faster Internet access than normal modems, there are several caveats to using an K56flex modem:

-The high speeds are available only with downstream traffic (e.g., data sent to your computer). Upstream traffic

is delivered using normal techniques, with a maximum speed of 33.6 Kbps. -To connect to the Internet at K56flex speeds, your Internet Service Provider (ISP) must have a modem at the other end that supports V.90. -Even if your ISP supports V.90, you might not achieve maximum transmission rates due to noisy lines.

• Kbit/s:

Stands for thousands of bits per second.

• Kerberos: The name ‘Kerberos’ was derived from Greek mythology which refers to the three-headed dog that guarded the gates of Hades. Kerberos is most widely used in a network to provide secure network authentication. Usually to authenticate users of the network.

• Kernel: The central module of an operating system. It is the part of the operating system that loads first, and it remains in main memory. Because it stays in memory, it is important for the kernel to be as small as possible while still providing all the essential services required by other parts of the operating system and applications. Typically, the kernel is responsible for memory management, process and task management, and disk management.

• Keygen: (Key Generator). Refers to a program that will automatically generate a registration or serial number. Its usual purpose is to eliminate software piracy.

• Kilobyte: (KB)

This is about a thousand bytes of space. In reality, it’s two to the 10th power or 1,024 bytes.

• KVM: Keyboard-Video-Mouse switch. A piece of hardware that connects two or more computers to a single keyboard, monitor and mouse. Imagine you have a row of 4 computers that all serve as file servers. Why waste money buying 4 monitors, 4 keyboards and 4 mice. With a KVM switch you can connect all 4 computers to one monitor, keyboard and mouse and to switch between them when needed.

• LAN: A computer network that spans a relatively small area. Most LANs are confined to a single building or group of buildings. However, one LAN can be connected to other LANs over any distance via telephone lines and radio waves. A system of LANs connected in this way is called a wide area network (WAN).

Most LANs connect workstations and personal computers. Each node (individual computer ) in a LAN has its own CPU with which it executes programs, but it is also able to access data and devices anywhere on the LAN. This means that many users can share expensive devices, such as laser printers, as well as data. Users can also use the LAN to communicate with each other, by sending e-mail or engaging in chat sessions.

There are many different types of LANs Ethernets being the most common for PCs. Most Apple Macintosh networks are based on Apple’s AppleTalk network system, which is built into Macintosh computers.

• Layer: In networking, layers (also called Levels) refer to software protocols. Each layer builds on the layer beneath it as part of an overall interactive transmission system.

• LBA: Known as: Logical Block Addressing. In a system using an enhanced BIOS andOperating System that supports the use of LBA, it would then be possible for the computer to use a larger hard drive. LBA allows for use of a unique sector number in each sector instead of referring to a cylinder, head and sector number configuration.

• LCD: Abbreviation of liquid crystal display, a type of display used in digital watches and many portable computers. LCD displays utilize two sheets of polarizing material with a liquid crystal solution between them. An electric current passed through the liquid causes the crystals to align so that light cannot pass through them. Each crystal, therefore, is like a shutter, either allowing light to pass through or blocking the light.

Monochrome LCD images usually appear as blue or dark gray images on top of a grayish-white background. Color LCD displays use two basic techniques for producing color: Passive matrix is the less expensive of the two technologies. The other technology, called thin film transistor (TFT) or active-matrix, produces color images that are as sharp as traditional CRT displays, but the technology is expensive. Recent passive-matrix displays using new CSTN and DSTN technologies produce sharp colors rivaling active-matrix displays.

• LED: Abbreviation of light emitting diode, an electronic device that lights up when electricity is passed through it. LEDs are usually red. They are good for displaying images because they can be relatively small, and they do not burn out. However, they require more power than LCDs.

• LimeWire: A peer-to-peer Gnutella file sharing client which allows network users share files. LimeWire is a free open source software.

• Linker: A program specifically designed to combine or link together a large number of programs forming a single executable instruction set for these programs that can be loaded in to the systems memory for quick execution.

• Linux: A version of UNIX that runs on a variety of hardware platforms including x86 PCs, Alpha, PowerPC and IBM’s product line. Linux is open source software, which is freely available; however, the full distribution of Linux along with technical support and training are available for a fee from vendors such as Red Hat Software and Caldera. Due to its stability, Linux has gained popularity with Internet Service Providers as the Operating System of choice for hosting Web servers.

• Live Script:

This is the former name of Java Script. There are few updates between the two.

• LLTD (Link Layer Topology Discovery):

A feature that helps users to troubleshoot their networks. LLTD automatically detects multiple network devices and gives a graphical presentation of the connected hardware to identify configuration errors.

• Logic:

This is broken down into two categories:

-Software Logic: The sequence of instructions performed by a program. -Hardware Logic: A set of circuit elements that perform a function.

• Login:

To attach to a computer. It has also come to represent your User ID command.

• Login Script:

This is the small text file that is run by the server gateway to make the attachment between it and your computer.

• Loopback: A diagnostic test that returns the transmitted signal back to the sending device after it has passed through a network or across a particular link. The returned signal can then be compared to the transmitted one. The discrepancy between the two help to trace the fault. When trying to locate a faulty piece of equipment, loopbacks will be repeated, eliminating satisfactory machines until the problem is found.

• LVD:

Low Voltage Differential. A differential logic scheme using lower voltage levels than HVD.

• MAC Address: In networking, Media Access Control (MAC) Address refers to the globally unique hardware address of an Ethernet network interface card.

• MAC layer:

Media Access Control sub layer in the network stack.

• Macro: A file containing a sequence of instructions that can be executed as one command. These commands can be in the form of a key, symbol or name. As an example, one symbol could represent a predefined list of commands.

• Mainframe: Mostly a mainframe is only a mainframe when compared to a desktop computer. It’s bigger and much more powerful. Sometimes it’s called a server or CPU.

• Matrix: As an Internet term, this would refer to computers setup within a network and all of them having to ability to exchange information. The Internet itself could be considered a Matrix.

• MAU: (Medium Attachment Unit): An Ethernet device used for sending and receiving transmissions between the AUI (Attachment Unit Interface) port of a station and the common medium of the Ethernet.

• MBR: Short for Master Boot Record, a small program that is executed when a computer boots up. Typically, the MBR resides on the first sector of the hard disk. The program begins the boot process by looking up the partition table to determine which partition to use for booting. It then transfers program control to the boot sector of that partition, which continues the boot process. In DOS and Windows systems, you can create the MBR with the FDISK /MBR command.

An MBR virus is a common type of virus that replaces the MBR with its own code. Since the MBR executes every time a computer is started, this type of virus is extremely dangerous. MBR viruses normally enter a system through a floppy disk that is installed in the floppy drive when the computer is started up. Even if the floppy disk is not bootable, it can infect the MBR.

• MCNS: Multimedia Cable Network System Partners Ltd. The consortium behind the DOCSIS standard for cable modems.

• Media:

.       Objects on which data can be stored. These include hard disks, floppy disks, CD-ROMs, and tapes.

.       In computer networks, media refers to the cables linking workstations together. There are many different types of transmission media, the most popular being twisted-pair wire (normal electrical wire), coaxial cable (the type of cable used for cable television), and fiber optic cable (cables made out of glass).

.       The form and technology used to communicate information. Multimedia presentations, for example, combine sound, pictures, and videos, all of which are different types of media.

• Megabyte: (MB)

About a million bytes of space. Actually it’s 2 raised to the 20th power or 1,048,576 bytes of space.

• Memory: Internal storage areas in the computer. The term memory identifies data storage that comes in the form of chips, and the word storage is used for memory that exists on tapes or disks. Moreover, the term memory is usually used as a shorthand for physical memory, which refers to the actual chips capable of holding data. Some computers also use virtual memory, which expands physical memory onto a hard disk.

Every computer comes with a certain amount of physical memory, usually referred to as main memory or RAM. You can think of main memory as an array of boxes, each of which can hold a single byte of information. A computer that has 1 megabyte of memory, therefore, can hold about 1 million bytes (or characters) of information.

• Memory Address: This refers to the actual location of physical memory. These unique identifiers are assigned at the systems boot process and are used to keep track of CPU and device information for later retrieval. This process is referred to a “Memory Mapping”.

• Metadata:

A collection of data that summarizes other data. This data is formatted to describe certain aspects of a web

page, such as:

-Name -Description -Title -Author

The metadata information is used by the search engines to define a web page. This information is not viewable on the web page.

• Microcomputer: A category of computer that is generally used for personal computing, for small business computing, and as a workstation attached to large computers or to other small computers on a network.

• Microprocessor: A silicon chip that contains a CPU. In the world of personal computers, the terms microprocessor and CPU are used interchangeably. At the heart of all personal computers and most workstations sits a microprocessor. Microprocessors also control the logic of almost all digital devices, from clock radios to fuel-injection systems for automobiles.

Three basic characteristics that differentiate microprocessors:

-Instruction set: The set of instructions that the microprocessor can execute. -Bandwidth: The number of bits processed in a single instruction. -Clock Speed: Given in megahertz (MHz), the clock speed determines how many instructions per second the processor can execute.

In both cases, the higher the value, the more powerful the CPU. For example, a 32-bit microprocessor that runs at 50MHz is more powerful than a 16-bit microprocessor that runs at 25MHz.

In addition to bandwidth and clock speed, microprocessors are classified as being either RISC (reduced instruction set computer) or CISC (complex instruction set computer).

• MIDI: Stands for Music Instrument Digital Interface. It allows a computer to store and replay a musical instrument’s output.

• MIFARE: A leading communication protocol for contactless and dual interface smart cards. MIFARE technology is used to transmit data between a card and a reader device. MIFARE technology is most widely used in the transportation industry where a person with a preprogrammed card would wave the card over a reader device to speed the ticketing process.

• MIME: Multi-purpose Internet Mail Extensions. A standard that allows for the attachment of files such as images, sounds and animations to electronic mail messages. This preset information is preloaded in to the Web server and the Internet browser software. In order for this to work, both the sender and receiver of the e-mail message must be MIME compatible.

• Minicomputer: A nearly obsolete term used to describe an older computer usually around the size of a refrigerator. This computer was used by businesses for processing transactions, accessing databases and running reports. These minicomputers typically accommodated between 10 – 300 users simultaneously.

• Minislot:

Basic timeslot unit used for upstream data bursts in the DOCSIS standard.

• Mirror: In computing. this means to make an identical copy something. Usually, web sites use this to provide multiple sources of the exact same information giving its audience reliable access to large downloads at multiple locations called Mirror Sites.

• Modem: This is a word created out of the beginning letters of two other words: MOdulation and DEModulation. The words mean the changing of data from digital (computer language) to analog (phone line language) and then back again. It represents the purpose of your computer’s modem.

• Mosaic: The first Web browser to have a consistent interface for the Macintosh, Windows, and Unix environments. It was created at the National Center for Supercomputing Applications (NCSA). The success of this browser is really responsible for the expansion of the Web.

• Motherboard: The main circuit board of a microcomputer. The motherboard contains the connectors for attaching additional boards. Typically, the motherboard contains the CPU, BIOS, memory, mass storage interfaces, serial and parallel ports, expansion slots, and all the controllers required to control standard peripheral devices, such as the display screen, keyboard, and disk drive. Collectively, all these chips that reside on the motherboard are known as the motherboard’s chipset.

On most PCs, it is possible to add memory chips directly to the motherboard. You may also be able to upgrade to a faster CP by replacing the CPU chip. To add additional core features, you may need to replace the motherboard entirely.

• MP3: Stands for MPEG (Moving Picture Expert Group) Audio Layer 3. This is a compression standard that was developed to create a small audio file size while keeping a high quality sound. The small file size allows the sound to be streamed or downloaded over the Internet with ease.

• MP4: Stands for MPEG (Moving Picture Expert Group) – 4. Finalized toward the end of 1998, this became an International Standard in the beginning of 1999. This was developed to provide low bandwidth multimedia applications.

• MPEG: Stands for Motion Picture Experts Group. A format to make, view, and transfer both digital audio and digital video files.

• MSO: Multiple Service Operator. A cable TV service provider that also provides other services such as data and/or voice telephony.

• MSQL (Mini Structured Query Language): A lightweight client/server database that is the popular choice for open source developers. It is designed to provide quick access to data while only requiring a small amount of memory.

• Multimedia Extensions (MMX): A technology created by Intel Corporation that enhances audio and video capabilities. MMX is found in Pentium III and later CPU’s and is also found in AMD K6 series CPU’s. Microprocessors that have MMX can handle tasks that usually are handled by a separate component, such as; Digital Signal Processing (DSP) is a common multimedia operation that is normally handled by a separate audio or video card. The direct benefit of this technology includes speeding up such things as; image processing, motion video, speech synthesis, telephony, and 3D graphics.

• Multiplexer: This is a piece of hardware that allows one item to take the place of several. An example would be using a multiplexer to allow 10 computers to attach where only one could before.

• Mux:

See Multiplexer

• NACS:

Stands for Netware Asynchronous Communication Services.

• Nanosecond: A billionth of a second. Many computer operations, such as the speed of memory chips, are measured in nanoseconds. Nanosecond is often abbreviated as ns.

• Native: The relationship between a transport user and a transport provider, both being based on the same transport protocol. Also, a specific software could be written to run on a specific processor, which would make that software ‘native’ to that processor.

• Netbeui: Netbeui is short for NetBios Enhanced User Interface. It is an enhanced version of the NetBIOS protocol used by network operating systems such as LAN Manager, LANServer, Windows for Workgroups, Windows 95 and Windows NT.

Netbeui was originally designed by IBM for their Lan Manager server and later extended by Microsoft and Novell.

• Network:

This a system that sends and receives data.

• Network Adapter: This is a hardware unit that connects a device to a communication line. For wide area networks (WAN), these adapters connect routers to the specific type of connection (T1, BRI) that is installed. For local area networks (LAN), these adapters connectworkstations to the LAN (Ethernet or TokenRing) cabling.

• Network Card: Also, Network Interface Card or NIC. This is a component of a computer that enables the computer to communicate with other computers via a direct network connection.

• Newsgroup: An online discussion community found on the USENET system. These groups cover thousands of different topics of information and are offered free of charge.

• NLX: New Low-Profile eXtended (motherboard form factor). The NLX form factor features a number of improvements over the previous design LPX form factor and began heavy usage in late 1997. The popularity of the design was confirmed by massive design use in 1998. The popularity has made it Intel’s flagship line and one of the profit leaders in chipsets. Its features include:

1. Support for larger memory modules and DIMMs.
2. Support for the newest microprocessors, including the Pentium II using SEC packaging.
3. Support for AGP video cards.
4. Better access to motherboard components.
5. Support for dockable designs in which the motherboard can be removed without tools.

• Node: In networks, a processing location. A node can be a computer or some other device, such as a printer. Every node has a unique network address, sometimes called a Data Link Control (DLC) address or Media Access Control (MAC) address.

• Noise: Interference (static) that destroys the integrity of signals on a line. Noise can come from a variety of sources, including radio waves, nearby electrical wires, lightning, and bad connections. One of the major advantages of fiber optic cables over metal cables is that they are much less susceptible to noise.

• NTFS: Short for NT File System, one of the file system for the Windows NT operating system (Windows NT also supports the FAT file system). NTFS has features to improve reliability, such as transaction logs to help recover from disk failures. To control access to files, you can set permissions for directories and/or individual files. NTFS files are not accessible from other operating such as DOS.

For large applications, NTFS supports spanning volumes, which means files and directories can be spread out across several physical disks.

• NTLDR: Short for NT Loader, a program loaded from the hard drive boot sector that displays the Microsoft Windows NT startup menu and helps Windows NT load.

• Null Value: In computer programming, this represents something of no value. A null value could also indicate that the value for a row is either missing or not known. Placing a zero in a row would not be representative of a null value because zero is a value.

• NUMA (Non-Uniform Memory Access): A method of configuring a cluster of microprocessor in a multiprocessing system so that they can communicate with each other, this improves performance and its expansion ability.

• NVRAM: (Non-Volatile Random Access Memory) Any type of memory that is made non-volatile by connecting it to a constant power source, such as a battery. Therefore, non-volatile memory does not lose its contents when the main power is turned off.

• Object:

Something that contains both the data and the application that operates on that data.

• ODBC Administrator: Developed by Microsoft for its Windows operating systems. The icon for the ODBC is named “Data Sources” and is located in the Control Panel under Administrative Tools in the Windows 2000 and XP operating systems. This Data Source Administrator is responsible for managing database drivers and configuring the user and system Data Source Names (DSN). A UNIX system does not use this method, its data source information is stored in text configuration files.

• OEM: (Original Equipment Manufacturer) This is a designation for companies that manufacture equipment that is then marketed and sold off to other companies under their own names.

• OOP:

Stands for Object Oriented Program. A larger program made up of smaller objects.

• Opacity: The quality that defines how much light passes through an object’s pixels. If an object is 100 percent opaque, no light passes through it.

• Operating System: The most important program that runs on a computer. Every general-purpose computer must have an operating system to run other programs. Operating systems perform basic tasks, such as recognizing input from the keyboard, sending output to the display screen, keeping track of files and directories on the disk, and controlling peripheral devices such as disk drives and printers.

For large systems, the operating system has even greater responsibilities and powers. It is like a traffic cop — it makes sure that different programs and users running at the same time do not interfere with each other. The operating system is also responsible for security, ensuring that unauthorized users do not access the system.

Operating systems provide a software platform on top of which other programs, called application programs, can run. The application programs must be written to run on top of a particular operating system. Your choice of operating system, therefore, determines to a great extent the applications you can run. For PCs, the most popular operating systems are DOS, OS/2, and Windows, but others are available, such as Linux.

As a user, you normally interact with the operating system through a set of commands. For example, the DOS operating system contains commands such as COPY and RENAME for copying files and changing the names of files, respectively. The commands are accepted and executed by a part of the operating system called the command processor or command line interpreter. Graphical user interfaces allow you to enter commands by pointing and clicking at objects that appear on the screen.

• Oracle: A high-end database management software created by Oracle Corporation. Oracle’s relational database pioneered the support of the SQL language which is now an industry standard.

• OSI Reference Model (Open Systems Interconnect): A network communications software standard that consists of a seven layer structure of specified protocol and services.

• Overclock: To run a microprocessor faster than the speed for which it has been tested and approved. Overclocking is a popular technique for eking out a little more performance from a system. In many cases, you can force your CPU to run faster than it was intended simply by setting a jumper on the motherboard. Overclocking does come with some risks, however, such as over-heating, so you should become familiar with all the pros and cons before you attempt it.

Overclocking is sometimes called speed margining.