Glossary 217

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baud rate — The speed at which a communication device, such as a printer or modem, transmits information. Baud rate is the number of signal changes per second (not necessarily the same as bits per second). See also bits per second.

BIOS (basic input/output system) — Basic instructions, stored in read-

only memory (ROM), containing the information the computer needs to check hardware and load the operating system when you start up the computer.

bits per second (bps) — A way of measuring the speed at which information is passed between two devices. This is the basic unit of measure used in modem communications, and is similar, but not identical, to the baud rate. See also baud rate.

boot — To start the computer. The term “boot” originates from bootstrap program (as in “pulling itself up by its bootstraps”), a program that loads and initializes the operating system. See also reboot.

boot disk — See system disk.

boot priority (startup sequence) — The order in which the computer accesses its disk drives to locate the startup files. Under the default startup sequence, the computer looks for the startup files in the diskette drive before checking the hard disk.

bus — An electrical circuit that connects the central processing unit (CPU) with other parts of the computer, such as the video adapter, disk drives, and ports. It is the pathway through which data flows from one device to another. See also bus speed, frontside bus.

bus speed — The speed at which the central processing unit (CPU) communicates with the other parts of the computer.

cache — A section of very fast memory in which frequently used information is duplicated for quick access. Accessing data from cache is faster than accessing it from the computer’s main memory. See also CPU cache, L1 cache, L2 cache.

CD — An individual compact disc. See also CD-ROM.

CD-ROM (compact disc read-only memory) — A form of high- capacity storage that uses laser optics instead of magnetic means for reading data. See also CD. Compare DVD-ROM.