Glossary 167GlossaryTerms in this Glossary are provided forinformational purposes only and may or may notdescribe features included with your particularcomputer.AAC — alternating current — The form of electricity thatpowers your computer when you plug the AC adapterpower cable in to an electrical outlet.ACPI — advanced configuration and power interface —A power management specification that enablesMicrosoft® Windows® operating systems to put acomputer in standby or hibernate mode to conserve theamount of electrical power allocated to each deviceattached to the computer.AGP — accelerated graphics port — A dedicated graphicsport that allows system memory to be used for video-related tasks. AGP delivers a smooth, true-color videoimage because of the faster interface between the videocircuitry and the computer memory.AHCI — Advanced Host Controller Interface — Aninterface for a SATA hard drive Host Controller whichallows the storage driver to enable technologies such asNative Command Queuing (NCQ) and hot plug.ALS — ambient light sensor — A feature that helps tocontrol display brightness.antivirus software — A program designed to identify,quarantine, and/or delete viruses from your computer.ASF — alert standards format — A standard to define amechanism for reporting hardware and software alerts to amanagement console. ASF is designed to be platform- andoperating system-independent.Bbattery life span — The length of time (years) duringwhich a portable computer battery is able to be depletedand recharged.battery operating time — The length of time (minutes orhours) that a portable computer battery powers thecomputer.BIOS — basic input/output system — A program (orutility) that serves as an interface between the computerhardware and the operating system. Unless youunderstand what effect these settings have on thecomputer, do not change them. Also referred to as systemsetup.bit — The smallest unit of data interpreted by yourcomputer.Bluetooth® wireless technology — A wireless technologystandard for short-range (9 m [29 feet]) networkingdevices that allows for enabled devices to automaticallyrecognize each other.boot sequence — Specifies the order of the devices fromwhich the computer attempts to boot.bootable media — A CD, DVD, or floppy disk that youcan use to start your computer. In case your hard drive isdamaged or your computer has a virus, ensure that youalways have a bootable CD, DVD, or floppy disk available.Your Drivers and Utilities media (or ResourceCD) is abootable CD or DVD.bootable disk — A disk that you can use to start yourcomputer. In case your hard drive is damaged or yourcomputer has a virus, ensure that you always have abootable CD, DVD, or floppy disk available.bps — bits per second — The standard unit for measuringdata transmission speed.BTU — British thermal unit — A measurement of heatoutput.bus — A communication pathway between thecomponents in your computer.bus speed — The speed, given in MHz, that indicates howfast a bus can transfer information.