A word typically made up of the first letters of two or more words; for example, BASIC stands for "Beginners All purpose Symbolic Instruction Code." Artificial intelligence is "AI." The computer industry is loaded with acronyms, and technicians love using them to the consternation of non-computer people.
If only the first letters of the words are used, the term is technically an "initialism," but this distinction is hardly ever made. Letters within a word and contiguous letters are widely used; for example, XML means "eXtensible Markup Language and MP4 stands for MPEG4. For the mother of all acronyms, see
TLA. See
backronym.