Glossary 191GlossaryA — Ampere(s).AC — Alternating current.ACPI — Advanced Configuration and Power Interface. A standard interface forenabling the operating system to direct configuration and power management.ambient temperature — The temperature of the area or room where the system islocated.ANSI — American National Standards Institute. The primary organization fordeveloping technology standards in the U.S.asset tag — An individual code assigned to a system, usually by an administrator, forsecurity or tracking purposes.backup — A copy of a program or data file. As a precaution, back up your system’shard drive(s) on a regular basis.blade — A module that contains a processor, memory, and a hard drive. The modulesare mounted into a chassis that includes power supplies and fans.bootable media — A diskette, USB memory key, or optical media that is used to startyour system in lieu of the hard drives.BTU — British thermal unit.bus — An information pathway between the components of a system. Your systemcontains an expansion bus that allows the processor to communicate with controllersfor the peripheral devices connected to the system. Your system also contains anaddress bus and a data bus for communications between the processor and RAM.C — Celsius.cache — A fast storage area that keeps a copy of data or instructions for quick dataretrieval.cm — Centimeter(s).COMn — The device names for the serial ports on your system. Serial ports can beeither physical or virtual.control panel — The part of the system that contains indicators and controls, such asthe power button and power indicator.controller — A chip or expansion card that controls the transfer of data between theprocessor and memory or between the processor and a peripheral device.coprocessor — A chip that relieves the system’s processor of specific processing tasks.A math coprocessor, for example, handles numeric processing.