A
- A-GPS
- A* search
- A0–A10
- A3
- A4
- A5
- A8
- AAA
- AAAI
- AAC
- AADL
- AAL
- AAL1
- AAS
- abandonware
- abbreviated address
- abbreviated dialing
- abbreviation
- ABC
- abend
- ABI
- Abilene Network
- ABNF
- abort (ABT)
- ABR
- ABRD
- ABS
- absolute address
- absolute cell reference
- absolute coding
- absolute delay
- absolute error
- absolute path
- absolute pressure sensor
- absolute program
- absolute time
- absolute zero
- abstract
- abstract class
- abstract data type
- abstract machine
- abstract syntax
- abstraction
- abstraction layer
- academic paper
- Academic Workload Management System
- Accelerated Mobile Pages
- acceleration
- acceleration hardware
- accelerator