Computer Glossary

Antivirus Software	Software specifically designed for the detection and prevention of known viruses.
Bandwidth	The speed at which a user is connected to the Internet
BIOS (Basic Input/Output System)	Pronounced "BY-ose," this is the interface between the hardware and software of a computer system. Also known as firmware, BIOS lets the operating system communicate with all input/output devices (such as video and sound cards, serial and parallel ports) and controls critical information for computer startup.
Bit	Short for binary digit, this is the smallest unit of data a computer can handle. Each bit has a value of 0 or 1, which a computer interprets as on or off. Eight bits make up one byte.
Bootable Diskette	A diskette that contains a computers minimal operating system functions and allows the PC to be started in emergencies, such as when a hard drive won't function normally. Also called a system or DOS diskette.
BPS	Bits per Second. Refers to the speed at which a modem can transmit data. Divide the bits per second by ten to get an approximate idea of how many characters per second a modem can transmit.
Bus	A linear electrical signal pathway for communication between various computer devices, such as the CPU, RAM, and peripherals (i.e.,printers).
Byte	Eight bits make up one byte. A byte is the equivalent of one alphanumeric character. Storage capacities such as hard drives, random-access memory, and diskettes usually are measured in kilobyte (one-thousand bytes) or megabytes (one million bytes).
CMOS-RAM (Complimentary Metal-oxide Semiconductor Random-access Memory)	This mouthful refers to a chip design that saves the computer’s startup information. It requires only minimal power (usually from a small battery) and remains intact when the computer’s main power is off.
Cookie	A small data file that is stored on a user's local computer for record-keeping purposes and which contains information about the user that is pertinent to a Web site, such as user preferences
CPU (Central Processing Unit)	The "brain" of the computer. The type of CPU, or microprocessor, that a computer has determines what type of system it is. The 80386, 80486, and Pentium are all processor chips, or CPUs.
Daughterboard	A circuit board attached to either another circuit board or the motherboard. These boards increase the capabilities of a computer.
Default Settings	Standard settings for a command or option that are predetermined by the computer, but can be changed by the user.
Dialog Box	An on-screen text box found in a graphical user interface, such as Windows, that provides information and possible options to the user.
DIMMs	Dual In-Line Memory Modules. Stackable memory that are thicker than SIMMS because the chips are actually stacked on top of one another. The most basic type of DIMMs stack entire modules (rather than chips) on top of each other.
Diskette Drive	A peripheral storage device that uses removable diskettes to store and retrieve data. Diskette drives are also called Floppy Drives, have the smallest capacity among storage media and are the slowest to operate. Diskette drives usually are used for backups and transporting files among PCs.
Download	To transfer a copy of a file from a remote computer to a requesting computer by means of a modem or network.
DRAM	Dynamic Random-access Memory. RAM that stores information in integrated circuits containing capacitors, which need to be electronically refreshed in order to remember what is in them.
Driver	Software that lets the computer communicate with hardware devices, such as a mouse, or other software.
Expansion Card	Electronic circuit cards that fit into slots in the main circuit board (motherboard) inside the case of the computer. A computer user can use expansion cards to add items such as internal modems, sound capability, and ports to a PC.
FAT	File Allocation Table. A table that operating systems use to keep track of the contents of a disk. The table is a chart of numbers that correspond to cluster addresses on the disk. When a program requests data from a disk, the operating system searches the FAT to locate it.
File Extension	A "tag" that identifies a file and is separated from the rest of the file name by a period. These extensions can indicate whether a file is an executable program (with an .exe extension), a text file (.txt), or any other type of file.
Firewall	Software or hardware that limits certain kinds of access to a computer from a network or outside source. Firewalls are commonly used to thwart would-be hackers from infiltrating computer systems.
Flash ROM	A type of ROM that can be electronically rewritten (flashed); this feature allows it to be reprogrammed without being removed from your system. Also known as EPROM.
GB (Gigabyte)	A common measurement of computer storage equaling about 1 billion bytes, or 1,000 megabytes.
GUI	Graphical User Interface. Software, such as Windows, that lets users control computer operation by pointing with a device, such as a mouse, to images and menus rather than typing commands.
Hacker	A technically sophisticated computer user who illegally breaks into a computer system to do damage, steal secrets, or get thrills.
Hard Drive	A peripheral storage device containing a non-removable disk or disks where data is stored and retrieved. Hard drives have the greatest storage capacity and the fastest data recall time among storage media.
HTML (Hypertext Markup Language)	The programming language that most Web pages are written in.
IDE	Integrated Drive Electronics. A standard for hard drive interfaces. IDE is different from Small Computer Systems Interface (SCSI) and Enhanced Small Device Interface (ESDI) because its controllers are on each drive, meaning the drive can connect directly to the motherboard. IDE and its successor, Enhanced IDE (EIDE), are the most common drive interfaces in PCs.
I/O Port	Short for Input/Output Port, a connector on the computer where you plug in a cable from another device and through which information can flow between the two units.
IRQ (Interrupt Request Lines)	The wires that connect the microprocessor to hardware devices. IRQs let the hardware components request their share of attention from the microprocessor. Each line has its own "address" in the computer’s memory.
ISP (Internet Service Provider)	These companies provide subscribers with access to the Internet for a fee. ISPs, unlike commercial online services, provide only a direct Internet connection without the instructions or interest catalogs that help you navigate through the available information.
KB	Kilobyte. A unit used to measure the capacity of a hard drive, diskette, or random-access memory. One kilobyte equals 1,024 bytes.
MB (Megabyte)	A common measurement of computer storage equaling approximately 1 million bytes.
Metasearch	Seeking to find Web sites through a number of search engines simultaneously.
MHz (Megahertz)	Used to measure a CPU’s speed, one megahertz is equal to about 1 million cycles per second.
Modem	Modulator/Demodulator. A device that lets a PC communicate and exchange information with other modem-equipped computers via telephone lines.
Motherboard	The main circuit board of the computer. Other components are connected or directly attached to the motherboard.
Newsgroups	A virtual area on the Internet reserved for discussion of a certain topic. A newsgroup might be controlled or moderated by an individual who monitors all messages transmitted to the area.
OLE (Object Linking and Embedding)	A way of sharing information between applications. A linked or embedded object created by one application can be placed in a document created by the same or a different application. With a linked file in a document, the document contains only a reference, or "link," to the real file, which resides elsewhere. With an object that is "embedded" in a document, the document actually contains a copy of the object file.
Offline Browsers	Software that retrieves Web sites for viewing when users are not online, saving time because retrieving data from a computer’s hard drive is faster than downloading it from the Internet and saving money on pay-per-hour charges.
Parallel Port	A port that accepts cables that have parallel wires letting data flow through the cable at high speed. Parallel ports can transfer data eight bits (one byte) at a time. Most printers use parallel ports, which are commonly referred to as LPT1 or LPT2.
Push Technology	Software engineered to retrieve Web sites and bring them to your computer rather than users actively seeking (pulling) them through search engines and other methods. Push technology makes the Internet experience more like television in that the user is more passive, viewing sites that are more pertinent to the user’s taste and preference.
RAM (Random-access Memory)	The temporary memory storage area used to load program instructions and store files currently in use. Unless a file is permanently stored on a hard drive, diskette, or other storage medium, changes to information in RAM will be lost when the computer is turned off.
ROM (Read-only Memory)	A type of memory that contains data that can be read but not changed.
SCSI	Small Computer System Interface. A small computer system interface used for connecting computers to peripheral devices, other computers, and local-area networks. Peripheral devices are attached to a single SCSI port on the computer through a series of connections called a daisy chain. Transmissions through a SCSI port occur one device at a time.
Search Engines	Also called search services, this system of constantly updated databases and retrieval tools lets users find links to Web sites based upon keywords and other information.
Serial Port	A port that transmits data one bit at a time. These ports are used for peripherals such as mice and other input devices.
Sound Card	An expansion card for your PC that generates sound and provides audio output to external amplifications devices, such as headphones or speakers. Also called a sound board or audio card.
SRAM (Static RAM)	A type of computer memory that requires a constant power flow to hold information. It’s quicker and more dependable than dynamic RAM, but it’s also more expensive, takes up more space, and uses more power. Therefore, SRAM is never used as the main RAM storage facility.
Shareware	Software that you can download for free from the Internet. If you decide to keep the program, you then pay a fee for it.
SIMM (Single In-line Memory Module)	A slender circuit board that contains the RAM chips. These circuit boards are attached to the motherboard via a SIMM socket.
Streaming	The playing of compressed sounds or images as they are being downloaded and uncompressed by a browser.
Swap File	Also known as virtual memory, a portion of a hard drive that is set aside for Windows to use when it runs out of RAM. These files can either be permanent (in a contiguous location on the hard drive) or temporary (placed wherever space is available).
Trojan Horse	A computer program that appears to be useful but that actually does damage.
Virus	Code written with the express intention of replicating itself. A virus attempts to spread from computer to computer by attaching itself to a host program. It may damage hardware, software, or data.
Worm	A subclass of virus. A worm generally spreads without user action and distributes complete copies (possibly modified) of itself across networks. A worm can consume memory or network bandwidth, thus causing a computer to stop responding.
Wizard	A feature included in some programs that provides a step-by-step guide to lead users through performing certain tasks in the program.