Compatibility Guide

136 Glossary
BTU
Abbreviation for British thermal unit.
bus
An information pathway between the components of a system. Your system
contains an expansion bus that allows the microprocessor to communicate with
controllers for all the various peripheral devices connected to the system. Your
system also contains an address bus and a data bus for communications between
the microprocessor and RAM.
byte
Eight contiguous bits of information, the basic data unit used by your system.
C
Abbreviation for Celsius.
CA
Abbreviation for certification authority.
cache
A fast storage area that keeps a copy of data or instructions for quicker data
retrieval. For example, your system's BIOS may cache ROM code in faster RAM.
Or, a disk-cache utility may reserve RAM in which to store frequently accessed
information from your system's disk drives; when a program makes a request to a
disk drive for data that is in the cache, the disk-cache utility can retrieve the data
from RAM faster than from the disk drive.
capability
Refers to the actions that an object can perform, or actions that can be taken on
a managed object. For example, if a card is hot-pluggable, it is capable of being
replaced while the system power is on.
CDRAM
Abbreviation for cached DRAM, which is a high-speed DRAM memory chip
developed by Mitsubishi that includes a small SRAM cache.
CD-ROM
Abbreviation for compact disc read-only memory. CD drives use optical
technology to read data from CDs. CDs are read-only storage devices; you cannot
write new data to a CD with standard CD drives.