A

AC (Alternating Current)

Current that changes from a positive voltage to a negative voltage during one cycle. An example is household electricity in the United States, which is 110V at 60Hz.

ACPI (Advanced Configuration and Power Interface)

A power management specification that makes better use of power by letting the operating system control the power provided to peripheral devices.

ADC or A/D (Analog-to-Digital Converter)

A component on a sound card that converts analog sound to a digital bit stream.

ADSL (Asymmetric Digital Subscriber Line)

A newer transmission technology in the global broadband access market. ADSL supports data rates from 1.5–9 Mbps when receiving data (known as the downstream rate) and from 16–640 Kbps when sending data (known as the upstream rate). Not only is ADSL winning devout followers with its impressive speed, but also quite impressively, such increased data flow occurs over existing copper telephone lines (POTS). With more than half the worlds broadband subscribers now using one variation of the technology or another, the long-term potential for this market is basically every phone line in the world.

AGP (Accelerated Graphics Port)

A 32/64-bit expansion interface available on newer PCs that supports fast, three-dimensional graphics and provides the video controller card with a dedicated path to the CPU. The most common internal standard (as of this writing) for computer video. Uses SVGA connectors for monitors.

algorithm

A mathematical formula designed to solve a problem by accounting for expected occurrences.

AMR (Audio Modem Riser)

A new architectural design for motherboards developed by Intel. This new design places the analog I/O audio functions along with a codec chip on a small board, or ‘riser.’ This separation of the analog functions from the motherboard means higher audio quality and more flexibility for manufacturers’ further design advancements, thus allowing them a way to side step the lengthy certification process of new motherboard designs.

ANSI (American National Standards Institute)

A nonprofit organization whose primary purpose is to develop standards for the information technology industry.

API (Application Program Interface)

A set of uniform routines or rules that allow programmers and developers to write applications that can be used to interact with various operating system platforms. APIs define system calls for service, and are the building blocks and tools used by programmers in building software applications.

APM (Advanced Power Management)

User-level program found in all modern laptop computers and most modern desktop systems. Its features, which can be disabled, include system standby and hibernate. For the best results, Microsoft recommends that you disable advanced power management in the BIOS, since BIOS may have settings that Windows cannot override.

applet

A small program within Windows that is used to configure certain aspects of hardware and software. The items in Control Panel are called applets—literally, “small applications.”

application

A computer program.

ARP (Address Resolution Protocol)

A TCP/IP protocol used to determine the hardware MAC address for a network interface card.

ASCII (American Standard Code for Information Interchange)

Specifies a 7-bit pattern that assigns numeric values to letters, numbers, punctuation marks, and certain other characters by standardizing the values used. ASCII enables communication between computers and peripherals by using numbers in place of characters.

ASR (Automated System Recovery)

Backup tool in Windows XP that creates an image of your boot partition for restoration in case of failure or replacement of the boot hard drive.

AT (Advanced Technology)

A discontinued form factor of case, motherboard, and power supply. IBM’s name for its 80286 PC that was introduced in 1984. The AT form factor refers to the layout of the components on a motherboard.

ATA (Advanced Technology Attachment)

The American National Standards Institute standard for IDE drives.

ATAPI (Advanced Technology Attachment Packet Interface)

Interface standards that allow devices such as CD-ROM drives, Iomega Zip drives, and tape backup drives to utilize IDE/ATA controllers. The standard for IDE optical drives.

ATX (Advanced Technology Extensions)

A more recent motherboard form factor that has replaced the AT form factor. ATX and its variations are the most commonly used form factors of case, motherboard, and power supply as of this writing. Variations include MicroATX and others