The following terms starting with the letter "A" have specific pages dedicated to them. You can come back to this page or the main Computer Terms page by using the navigation breadcrumbs at the bottom of each page.

• A/D = Analog to Digital
• A/V = Audio/Visual
• AAC = Advanced Audio Coding
• AARP = AppleTalk Address Resolution Protocol
• ABBH = Average Bouncing Busy Hour
• ABC = Atanasoff-Berry Computer
• ABEND = Abnormal End
• AC = Alternating Current
• ACD = Automatic Call Distributor
• ACeS = Asia Cellular Satellite System
• ACK = Acknowledge Character
• ACL = Access Control List
• ACM = Association for Computing Machinery
• ACPI = Advanced Configuration and Power Interface
• ACTA = America's Carriers Telecommunications Association
• ACU = Automatic Calling Unit
• ADB = Apple Desktop Bus
• ADCCP = Advanced Data Communications Control Protocol
• ADO = ActiveX Data Objects
• ADP = Automatic Data Processing
• ADPCM = Adaptive Differential Pulse Code Modulation
• ADS = Alternate Data Streams
• ADSL = Asymmetric Digital Subscriber Line
• ADVEIS = Anti-Virus Dependent Vulnerabilities in E-mail Infrastructure Security
• AES = Asynchronous Event Scheduler
• AFAIK = As Far As I Know
• AGP = Accelerated Graphics Port
• AH = Authentication Header
• AI = Artificial Intelligence
• AIFF and AIFF-C = Audio Interchange File Format
• AIML = Astronomical Instrument Markup Language
• AIX = Advanced Interactive Executive
• ALGOL = Algorithmic Language
• ALU = Arithmetic (and) Logic Unit
• AMANDA = Advanced Maryland Automatic Network Disk Archiver
• AMD = Advanced Micro Devices
• AML = Astronomy Markup Language
• AMP = Advanced Metal Powder
• AMPS = Advanced Mobile Phone System
• AMS = American Mobile Satellite Corporation
• AN = Active Network
• ANSA = Adaptive Network Security Alliance
• ANSI = American National Standards Institute
• AOL = America Online
• APA = All Points Addressable
• API = Application Program(ming) Interface
• APM = Advanced Power Management
• APP = Application Portability Profile
• APWG = Anti-Phishing Working Group
• ARLL = Advanced Run Length Limited
• ARM = Advanced (Acorn) RISC Machine
• ARM = Advanced RISC Machines Ltd
• ARP = Address Resolution Protocol
• ARPA = Advanced Research Projects Agency
• ARQ = Automatic Repeat Request
• ASAP = Activate Secure Authentication Protocol
• ASAP = As Soon As Possible
• ASCII = American Standard Code for Information Interchange
• ASF = ActiveMovie Streaming Format
• ASIC = Application-Specific Integrated Circuit
• ASP = Active Server Pages
• ASP = Application Service Provider
• ASP = Association of Shareware Professionals
• AT = Attention
• ATA = AT Attachment
• ATL = Active (ActiveX) Template Library
• ATM = Asynchronous Transfer Mode
• AUI = Attachment Unit Interface
• AVI = Audio/Video Interleaved format
• AWHFY = Are We Having Fun Yet
• AWT = Abstract Windows Toolkit