| ACL | Access Control List | - | Computer and Internet |
| ADC | Analog-to-Digital Converter | - | Computer and Internet |
| ADF | Automatic Document Feeder | - | Computer and Internet |
| ADSL | Asymmetric Digital Subscriber Line | - | Computer and Internet |
| AGP | Accelerated Graphics Port | - | Computer and Internet |
| AIFF | Audio Interchange File Format | - | Computer and Internet |
| AIX | Advanced Interactive Executive | - | Computer and Internet |
| ANSI | American National Standards Institute | - | Computer and Internet |
| API | Application Program Interface | - | Computer and Internet |
| ARP | Address Resolution Protocol | - | Computer and Internet |
| ASCII | American Standard Code For Information Interchange | - | Computer and Internet |
| ASP | Active Server Page | - | Computer and Internet |
| ASP | Application Service Provider | - | Computer and Internet |
| ATA | Advanced Technology Attachment | - | Computer and Internet |
| ATM | Asynchronous Transfer Mode | - | Computer and Internet |
