Hardware and Networking Terms Glossary for the Letter A

All Things A

AC – Alternating Current

Electricity running from the wall outlet. 120 Volts at 60Hz through a fuse or circuit breaker that can typically handle around 15-20 Amps.

Access Light

The LED on the front of a device indicating that it is reading or writing data.

Access Time

The time that elapses from the moment information is requested and the information is delivered. Usually given in nanoseconds (ns) for memory chips and milliseconds (ms) for disk drives.

ACPI – Advanced Configuration and Power Interface

A standard developed by Intel, Toshiba, and Microsoft that implements advanced power managment functions through the operating system. Also known as APM (advanced power management).

Active Matrix

A type of LCD (liquid crystal display) screen containing at least one transistor for every pixel on the screen. Also known as TFT.

Adapter

A device that serves as an interface between dissimilar devices. Often also called a circuit board, or card, but can also refer to a connector or cable adapter that changes connection types from one to another.

Address

The location of a particular piece of data or other information found on a computer.

Address Bus

One or a series of electrical conductors that are used to carry the binary address from the microprocessor to the rest of the system.

ADSL – Asymmetric Digital Subscriber Line

High speed transmission technology commonly used for Internet access. ADSL sends information asymmetrically, meaning data travels faster one way than the other. Original application was a T1 line, though it is now available in many different speeds and configurations.

AGP – Accelerated Graphics Port

A dedicated interface between the video adapter and the motherboard’s North Bridge. AGP is 32 bits wide and runs at 66MHz base speed. It can transmit 1, 2, 4, or 8 bits per cycle – marketed as 1x, 2x, 4x or 8x. This is an older standard that is quickly becoming entirely unsupported.

Ampere – AKA Amp

Basic unit for measuring electrical current.

Antialiasing

Software designed to make diagonal or curved lines appear smooth and continuous. Aliasing refers to undesirable visual effects in computer generated images caused by low sampling. Antialiasing seeks to correct this.

Anti-Static Mat

A pad on which computer components should be placed to prevent damage through electro-static discharge (ESD). May also refer to a large floor mat placed below a computer desk to discharge static from the technician while he is servicing the computer and components.

Antivirus

Software that prevents files containing viruses from being executed on a computer, as well as detects, repairs, and removes infected files.

Application

Software for the end-user like office productivity, games, web browsers, etc.

Archive Bit

The bit in a file’s attribute byte that indicates whether the file has been modified since the last time it was backed up.

ASCII – American Standard Code for Information Interchange

The commonly used 256 character set containing letters, numbers, and special characters. The graphical representation of a single byte. eg: the letter N contains 8 bits (1 byte) indicating how it should be displayed on screen.

ATAPI – AT Attachment Packet Interface

A specification that defines device-side characteristics for IDC peripherals like CD-ROM and tape drives.

ATM – Asynchronous Transfer Mode

A high-bandwidth low delay transmission technology.

ATX

A common motherboard form factor that has been in use since 1995 characterized by a double row of rear external I/O (input/output) connectors. Memory and CPU locations are designed not to interfere with the installation of expansion cards.

Available Memory

Memory not currently in use by the operating system, drivers, or applications.

Average Access Time

The average time it takes for a disk drive to begin reading data placed anywhere on the drive. This includes seek time and latency.

Average Seek Time

The average amount of time it takes to move the heads of a hard disk from one random cylinder location to another. Often defined as the seek time across one third of the total number of cylinders.

This post is part of the series: Computer and Network Hardware Glossary of Common Terms

Complete glossary of terms and definitions for common computer and network hardware. Learn the meanings of things relevant to your life as a computer user or professional.
  1. Glossary of Computer Hardware Terms: Numbers and Symbols
  2. Glossary of Computer Hardware Terms – The Letter A
  3. Glossary of Computer Hardware Terms – The Letter B
  4. Glossary of Computer Hardware Terms – The Letter C
  5. Glossary of Computer Hardware Terms – The Letter D
  6. Glossary of Computer Hardware Terms – The Letters E & F
  7. Glossary of Computer Hardware Terms – The Letters G & H
  8. Glossary of Computer Hardware Terms – The Letter I
  9. Glossary of Computer Hardware Terms – The Letters J, K, and L
  10. Glossary of Computer Hardware Terms – The Letter M
  11. Glossary of Computer Hardware Terms – The Letters N & O
  12. Glossary of Computer Hardware Terms – The Letter P
  13. Glossary of Computer Hardware Terms – The Letters Q & R
  14. Glossary of Computer Hardware Terms – The Letter S
  15. Glossary of Computer Hardware Terms – The Letters T & U
  16. Glossary of Computer Hardware Terms – The Letters V, W, & Z