Addressing APM – Advanced Power Management APT – Advanced Packaging Tool; cyberbezpieczeństwie: ATP – Advanced Persistent Threat AR – Augmented Reality ARM – Advanced RISC Machine (pierwotnie Acorn RISC Machine) ARP – Address Resolution Protocol ASCII – American Standard Code for Information Interchange ASIC – Application Specific Integrated Cicruit ASIO – Audio Stream Input/Output AS – Application Server ASMP – ASymmetric Multi Processing ASP – Active Server Pages AT – Advanced Technology ATA – Advanced Technology Attachment lub Analogue Telephone Adapter ATAPI – Advanced Technology Attachment Packet Interface ATM – Asynchronous Transfer Mode ATX – Advanced Technology Extended AT&T – American Telephone and Telegraph AVI – Audio Video Interleave AWS – Amazon Web Services