Computer Terms F-J

• FAT: Stands for File Allocation Table. Basically this is a table of contents in a directory that tells the computer what all is in there. Look at your Netscape cache, you’ll see a FAT. It’ll be the first file.

• FAT 16: This was an older FAT (File Allocation Table) that was designed for use in the MS-DOS system. FAT 16 was used in many Windows Operating Systems up to Windows ME. Its biggest downfall was that it could only handle small partition sizes.

• FAT 32: A new version of the file allocation table (FAT) available in Windows 95 OSR 2 and Windows 98. FAT32 increases the number of bits used to address clusters and also reduces the size of each cluster. The result is that it can support larger disks (up to 2 terabytes) and better storage efficiency (less slack space).

• Fault Tolerance: The ability of a system to respond gracefully to an unexpected hardware or software failure. There are many levels of fault tolerance, the lowest being the ability to continue operation in the event of a power failure. Many fault-tolerant computer systems mirror all operations — that is, every operation is performed on two or more duplicate systems, so if one fails the other can take over.

• FAQ: Stands for Frequently Asked Questions. An FAQ is a file or document where a moderator or administrator will post commonly asked questions and their answers.

• Fax Modem: A device you can attach to a personal computer that enables you to transmit and receive electronic documents as faxes. A fax modem is like a regular modem except that it is designed to transmit documents to a fax machine or to another fax modem. Some, but not all, fax modems do double duty as regular modems. As with regular modems, fax modems can be either internal or external. Internal fax modems are often called fax boards.

• FDDI: Fiber Distributed Data Interface — A standard for transmitting data on optical fiber cables at a rate of around 100,000,000 bits-per-second (10 times as fast as Ethernet, about twice as fast as T-3).

• FDISK: A program found in all Aptiva software loads that allows modification of the partitions and/or logical drives on the hard drive. It can Display, Delete and Create partitions and logical drives, defining them for DOS, OS/2 or Windows, depending on which version of FDISK is used and how it is used. Type FDISK and hit Enter to start the program. This is a DESTRUCTIVE command and incorrect use will result in data loss!

• Fetch: The process of ‘fetching’ a data or instruction item from memory and writing it to a register. The ‘fetched’ item is then either executed (instruction), or acted upon (data).

• Fiber Optic: An alternative to copper wire for transmitting information. In fiber optics, pulses of light representing binary data are flashed along a flexible glass fiber. The advantage over copper wiring is that a single strand of optical fiber can carry thousands and thousands of different frequencies at once without data loss.

• File Sharing: This is the most important feature of the Internet. This is a method of allowing one server to give the same file to many different end users.

• File Server: A computer or a file storage device on a network that allows other computers on the same network access to stored information and resources.

• Firmware: Software (programs or data) that has been written onto read-only memory (ROM). Firmware is a combination of software and hardware. ROMs, PROMs and EPROMs that have data or programs recorded on them are firmware.

• Flash Memory: This type of non-volatile memory has the ability to retain its information even when there is no power source. Flash Memory is best known for its use in hand help devices where it is used to store the operating system and core applications. Other devices that use Flash Memory are:

-Digital Cameras -Audio Players -Cell Phones and Pagers -USB Drives -Printers

• Flow Chart: A graphical representation of planned activities, operations or tasks. Usually, flow charts are used to show the progress of a certain activity. They can also be used to show the variance between specific operations.

• Formal Specification: These specifications exist to satisfy predefined properties of a device or program. The word “formal” in Computer Science is referring to the act of being “precise”. It takes three language components to make a specification “formal”:

1. Syntax: Grammatical structuring of data using a special code that defines how this special code is used to form words, phrases or any other allowable constraint.
2. Semantics: A relationship between words, phrases or any other allowable constraint and their actual meaning. This is contrast to “Syntax”. An example could be; if you enter a misspelled command, it would be a syntax error, but if you enter what may be a legitimate command but is not understood in its current context, this would be a “semantics error”.
3. Proof Theory: This deals with the actual “logic” of the programming. Using mathematical analysis techniques, the programming language is proof checked.

• Forms: A web page element that uses text fields, radio buttons and check boxes to process predefined data. Forms also allow users to interact with an application by allowing information to be passed dynamically between two points.

• FORTRAN: FORmula TRANslator. Developed in 1954 by IBM, it is a high-level programming language, most widely used for scientific and engineering applications because it has excellent mathematical functions. Many programmers consider it to sacrifice “elegance” for speed of numerical manipulations.

• Freeware:

This is a shortened version of Free Software. Programmers offer their work without wanting pay in return.

• Front Side Bus:
• FTP:

This is the main pathway for data transfer in a PC. It connects all of a computers major components, such as; memory, AGP socket and chipset.

Stands for File Transfer Protocol.

• Full Duplex: Refers to the transmission of data in two directions simultaneously. For example, a telephone is a full-duplex device because both parties can talk at once. In contrast, a walkie-talkie is a half-duplex device because only one party can transmit at a time.

Most modems have a switch that lets you choose between full-duplex and half-duplex modes. The choice depends on which communications program you are running.

In full-duplex mode, data you transmit does not appear on your screen until it has been received and sent back by the other party. This enables you to validate that the data has been accurately transmitted. If your display screen shows two of each character, it probably means that your modem is set to half-duplex mode when it should be in full-duplex mode.

• Gateway: As in Common Gateway Interface (CGI). It is a piece of software that allows two items to communicate with each other. They are used to make connections betweencomputers and systems inside that computer.

• General Protection Fault: GPF, short for General Protection Fault, is a computer condition that causes a Windows application to crash. The most common cause of a GPF is two applications trying to use the same block of memory, or more specifically, one application trying to use memory assigned to another application.

The following situations can also cause GPFs:

Running an application with insufficient resources Using improper hardware device drivers Corrupted or missing Windows files Applications exchanging data that cannot be read GPFs are often preceded by an invalid page fault.

• GIF:

Pronounced “jif.” Stands for Graphical Interchange Format. It is an image format created by Compuserve.

• Gigabyte: 2 to the 30th power (1,073,741,824) bytes. One gigabyte is equal to 1,024 megabytes. Gigabyte is often abbreviated as G or GB.

• GIGO:

It’s an acronym that stands for Garbage In, Garbage Out.

• Glyph: A graphic symbol whose appearance conveys information; for example, the vertical and horizontal arrows on cursor keys that indicate the directions in which they control cursor movement.

• Gopher: A method of distributing information by computers that has waned in popularity to ftp. Most gopher files contain only text information with few images, audio, or video components. Files can be downloaded with a similar protocol like ftp.

• GUI – Graphical User Interface: A program interface that takes advantage of the computer’s graphics capabilities to make the program easier to use. Well-designed graphical user interfaces can free the user from learning complex command languages. On the other hand, many users find that they work more effectively with a command-driven interface, especially if they already know the command language.

• Half-Duplex: Refers to the transmission of data in just one direction at a time. For example, a walkie-talkie is a half-duplex device because only one party can talk at a time. In contrast, a telephone is a full-duplex device because both parties can talk simultaneously.

Most modems contain a switch that lets you select between half-duplex and full-duplex modes. The correct choice depends on which program you are using to transmit data through the modem.

In half-duplex mode, each character transmitted is immediately displayed on your screen. (For this reason, it is sometimes called local echo — characters are echoed by the local device). In full-duplex mode, transmitted data is not displayed on your monitor until it has been received and returned (remotely echoed) by the other device. If you are running a communications program and every character appears twice, it probably means that your modem is in half-duplex mode when it should be in full-duplex mode, and every character is being both locally and remotely echoed.

• Handshaking:

The process by which two devices initiate communications. Handshaking begins when one device sends a message to another device indicating that it wants to establish a communications channel. The two devices then send several messages back and forth that enable them to agree on a communications protocol.

• Hard Boot: A hard reboot (also known as a cold reboot) is when power to a computer is cycled (turned on and off) or a special reset signal to the processor is triggered (from a front panel switch of some sort). This restarts the computer without first performing the usual shut-down procedure. (With many operating systems, especially those with disc caches, after a hard reboot the system may well be in an “unclean” state, and require that checks and repairs to on-disc filesystem structures be performed before normal operation can begin.) It may be caused by power failure, be done by accident, or be done deliberately as a last resort because nothing else to retrieve the system from a “hung” state works.

• Hardware:

These are the physical items including your computer and floppy discs.

• Hayes Compatible: Hayes Microcomputer Products is one of the leading manufacturers of modems and has developed a language called the AT command set for controlling modems that has become the de facto standard. Any modem that recognizes Hayes modem commands is said to be Hayes-compatible.

This is very useful because most communications programs use Hayes modem commands. Virtually all modems manufactured today are Hayes-compatible.

• Headend: Central distribution point for a CATV system. Video signals are received here from satellites and maybe other sources, frequency converted to the appropriate channels, combined with locally originated signals, and rebroadcast onto the HFC plant. The headend is where the CMTS is normally located.

• Heat Sink: A component designed to lower the temperature of an electronic device by dissipating heat into the surrounding air. All modern CPUs require a heat sink. Some also require a fan. A heat sink without a fan is called a passive heat sink; a heat sink with a fan is called an active heat sink. Heat sinks are generally made of a zinc alloy and often have fins.

• Helper Application:

This is an application your browser uses to manipulate a downloaded program.

• HFC: Hybrid fiber-coaxial (cable network). Older CATV systems were provisioned using only coaxial cable. Modern systems use fiber transport from the headend to an optical node located in the neighborhood to reduce system noise. Coaxial cable runs from the node to the subscriber. The fiber plant is generally a star configuration with all optical node fibers terminating at a headend. The coaxial cable part of the system is generally a trunk-and­branch configuration.

• High Memory Area:

In DOS -based systems, the high memory area refers to the first 64K of extended memory.

• HST: High Speed Technology-Before the invention of the CCITT V.32 modem standards for 9600 BPS modems, US Robotics invented a proprietary protocol that runs even faster at 14,400 BPS. It became popular on US bulletin board system, but never caught on outside the USA. It is gradually being replaced by V.32.

• Host: A computer on a network that provides services to other computers on the network. Unless you have your own server, you need a hosting company who provides a server or computer that is connected to the internet and makes your web pages available to the rest of the internet.

• Hot Fix:

Novell, Inc.’s term for the feature of their network file server operating system, Novell NetWare, which handles

errors in disk write operations. The OS re-reads every block it writes to disk while it holds the data to be written in memory. In the case of an error, the data block is written to a spare area on the disk.

The feature lost much of its importance with the widespread use of hard disk drives with built-in error correction and bad block re-mapping.

• Hotlist:

List of URLs saved within the Mosaic Web browser. (Bookmark in Netscape.)

• Hot Swappable: This refers to a device that is designed to be removed or replaced while a system is turned on without disturbing the computers function. A good example of a hot swappable device is the USB flash drive.

• HTML:

Hyper Text Markup Language. It is a collection of structuring and formatting tags used to create Web pages.

• HTTP: Stands for HyperText Transport Protocol. Common protocol used to communicate between World Wide Web Servers.

• Hub: A common connection point for devices in a network. Hubs are commonly used to connect segments of a LAN. A hub contains multiple ports. When a packet arrives at one port, it is copied to the other ports so that all segments of the LAN can see all packets.

A passive hub serves simply as a conduit for the data, enabling it to go from one device (or segment) to another. So-called intelligent hubs include additional features that enables an administrator to monitor the traffic passing through the hub and to configure each port in the hub. Intelligent hubs are also called manageable hubs.

A third type of hub, called a switching hub, actually reads the destination address of each packet and then forwards the packet to the correct port.

• Hybrid: A device or system combining two types of mechanisms, circuits, or design approaches, each of which could of itself accomplish the total function but in a different and usually less effective manner. A hybrid computer combines digital and analog computers into one functioning system.

• Hypertext: This is a mark-up language that allows for non-linear transfers of data. The method allows your computer to provide the computational power rather than attaching to a mainframe and waiting for it to do the work for you.

• Hyper-Threading: (HTT = Hyper Threading Technology) is Intel’s trademark for their implementation of the simultaneous multithreading technology on the Pentium 4 microarchitecture. It is basically a more advanced form of Super-threading that first debuted on the Intel Xeon processors and later added to Pentium 4 processors.

• IBM:

Stands for International Business Machines

• ICMP: (Internet Control Message Protocol) A message control and error-reporting protocol between a host server and a gateway to the Internet. ICMP uses Internet Protocol (IP) datagrams, but the messages are processed by the IP software and are not directly apparent to the application user.

• Icon:

A small video display that acts as an activation link when clicked on.

• IDE: (Integrated Development Environment) A programming environment integrated into an application. For example, Microsoft Office applications support various versions of the BASIC programming language. You can develop a

WordBasic application while running Microsoft Word.

• IIS (Internet Information Server):

A Web server that runs on the Windows NT/2000 platforms. It allows the creation of web-based applications. IIS provides both FTP server and web server capability.

• Image Map:

Typically, an image map is graphical representation (also known as “hot spots”) containing predefined clickable hyperlinks. A good example of an image map would be a map containing clickable outlined images of each city. Once the user clicks the image, they are taken to a seperate web page containing information regarding that particular city.

• IMAP:

Internet Message Access Protocol IMAP is gradually replacing POP as the main protocol used by email clients in communicating with email servers. Using IMAP, an email client program can not only retrieve email but can also manipulate messages stored on the server without having to actually retrieve the messages. So messages can be deleted, have their status changed, multiple mail boxes can be managed, etc.

• Infrared: A light that is so red that it is not viewable to the naked eye. It uses this invisible beam of light to transmit a pre-programmed ‘line-of-sight’ signal to certain electronic components. Its typical use involves wireless devices such as a TV remote controller.

• Instruction Set:

The set of instructions that the microprocessor can execute.

• Integrated Circuit:

Another name for a chip, an IC is a small electronic device made out of a semiconductor material.

• Interface: This is any type of point where two different things come together. Most often, the term is used to describe the programs between you and your computer like Windows, OS/2 and others. What you see on the screen is the interface between you and what your computer is doing.

• Interlacing: A display technique that enables a monitor to provide more resolution inexpensively. With interlacing monitors, the electron guns draw only half the horizontal lines with each pass (for example, all odd lines on one pass and all even lines on the next pass). Because an interlacing monitor refreshes only half the lines at one time, it can display twice as many lines per refresh cycle, giving it greater resolution. Another way of looking at it is that interlacing provides the same resolution as non-interlacing, but less expensively.

• Interleaving: A recording method that reduces data errors during playback. Instead of the file being written in a contiguous data stream, the data sectors are intermixed along the recording track. If a disc should have a smudge or scratch, the entire data file is generally recoverable because a smaller amount of the file data is affected.

• Internal Modem: A modem that resides on an expansion board that plugs into a computer. In contrast, an external modem is a box that attaches to a computer’s COM port via cables.

• Internet: The Internet is a super-network. It connects many smaller networks together and allows all the computers to exchange information with each other. To accomplish this all the computers on the Internet have to use a common set of rules for communication. Those rules are called protocols, and the Internet uses a set of protocols called TCP/IP (Transmission Control Protocol/Internet Protocol). Many people equate the World Wide Web with the Internet. In fact, the Internet is like the highway, and the World Wide Web is like a truck that uses that highway to get from place to place.

• Interrupt: A signal informing a program that an event has occurred. When a program receives an interrupt signal, it takes a specified action (which can be to ignore the signal). Interrupt signals can cause a program to suspend itself temporarily to service the interrupt.

Interrupt signals can come from a variety of sources. For example, every keystroke generates an interrupt signal. Interrupts can also be generated by other devices, such as a printer, to indicate that some event has occurred. These are called hardware interrupts. Interrupt signals initiated by programs are called software interrupts. A software interrupt is also called a trap or an exception.

PCs support 256 types of software interrupts and 15 hardware interrupts. Each type of software interrupt is associated with an interrupt handler — a routine key on your keyboard, this triggers a specific interrupt handler. The complete list of interrupts and associated interrupt handlers is stored in a table called the interrupt vector table, which resides in the first 1 K of addressable memory.

• Intranet: A private network for communications and sharing of information that, like the Internet, is based on TCP/IP but is accessible only to authorized users within an organization. An organization’s intranet is usually protected from external access by a firewall. See also: Extranet.

• IPsec: Stands for Internet Protocol Security. A set of protocols developed by IETF (Internet Engineering Task Force) and designed to provide protection of sensitive data over unprotected public networks, such as the Internet.

• IPX: Short for Internetwork Packet Exchange, a networking protocol used by the Novell NetWare operating systems. Like UDP/IP, IPX is a datagram protocol used for connectionless communications. Higher-level protocols, such as SPX and NCP, are used for additional error recovery services. The successor to IPX is the NetWare Link Services Protocol (NLSP).

• IS:

Stands for Information System.

• ISA: The bus architecture used in the IBM PC/XT and PC/AT. It’s often abbreviated as ISA (pronounced as separate letters or as eye-sa) bus. The AT version of the bus is called the AT bus and became a de facto industry standard. Starting in the early 90s, ISA began to be replaced by the PCI local bus architecture. Most computers made today include both an AT bus for slower devices and a PCI bus for devices that need better bus performance.

In 1993, Intel and Microsoft introduced a new version of the ISA specification called Plug and Play ISA. Plug and Play ISA enables the operating system to configure expansion boards automatically so that users do not need to fiddle with DIP switches and jumpers.

• ISDN: Integrated Services Digital Network. ISDN is a public global network capable of transmitting voice, data and images at speeds up to 2 Mbit/s. The digital technique can transport more signals on the same telephone line than the traditional analogue technique and enables a range of new services.

• ISO: Stands for the International Standards Organization. Someone has to say what is the standard for transferring data. These people are it. You’ll find them in Paris.

• ISP: Internet Service Provider, a company that provides access to the Internet. For a monthly fee, the service provider gives you a software package, username, password and access phone number. Equipped with a modem, you can then log on to the Internet and browse the World Wide Web and USENET, and send and receive e-mail.

In addition to serving individuals, ISPs also serve large companies, providing a direct connection from the company’s networks to the Internet. ISPs themselves are connected to one another through Network Access Points (NAPs). ISPs are also called IAPs (Internet Access Providers).

• ISDN: Integrated Services Digital Network. Basically a way to move more data over regular existing phone lines. ISDN is available to much of the USA and in most markets it is priced very comparably to standard analog phone circuits. It can provide speeds of roughly 128,000 bits-per-second over regular phone lines. In practice, most people will be limited to 56,000 or 64,000 bits-per-second. Unlike DSL, ISDN can be used to connect to many different locations, one at a time, just like a regular telephone call, as long the other location also has ISDN.

• Italics: A type style with slightly slanted characters, used for emphasis. Best used to set off quotes, special phrases, and foreign words, italic letters have a redesigned structure that allows them to slant to the right. The first italic type was designed by Aldus Manutius in AD 1501 and was based on the handwriting style of that time. Furthermore, lowercase letters were in italics while capital letters were Roman (or vertical stance).

• JAVA: A high-level programming language developed by Sun Microsystems. Java was originally called OAK, and was designed for handheld devices and set-top boxes. Oak was unsuccessful so in 1995 Sun changed the name to Java and modified the language to take advantage of the burgeoning World Wide Web.

Java is an object-oriented language similar to C++, but simplified to eliminate language features that cause common programming errors. Java source code files (files with a .java extension) are compiled into a format called bytecode (files with a .class extension), which can then be executed by a Java interpreter. Compiled Java code can run on most computersbecause Java interpreters and runtime environments, known as Java Virtual Machines (VMs), exist for most operating systems, including UNIX, the Macintosh OS, and Windows. Bytecode can also be converted directly into machine language instructions by a just-in-time compiler (JIT).

Java is a general purpose programming language with a number of features that make the language well suited for use on the World Wide Web. Small Java applications are called Java applets and can be downloaded from a Web server and run on your computer by a Java-compatible Web browser, such as Netscape Navigator or Microsoft Internet Explorer.

• JavaScript: This is a language very close to Java that allows for more interaction with the viewer. It is much more forgiving than Java as doesn’t require it’s own window in which to work.

• JPEG: Pronounced “J-Peg.” Stands for Joint Photographic Experts Group. It’s an image format that allows for compression when stored.

• Jumpers: A metal bridge that closes an electrical circuit. Typically, a jumper consists of a plastic plug that fits over a pair of protruding pins. Jumpers are sometimes used to configure expansion boards. By placing a jumper plug over a different set of pins, you can change a board’s parameters.

• JIT (Just-In-Time):

This is a type of Java compiler that interprets a class file, then compiles the information into native code.