sid - Computer Definition
(1) (Society for Information Display, Santa Ana, CA, www.sid.org) A membership organization founded in 1962 devoted to the information display industry. With chapters around the world, SID hosts conferences in the U.S. and abroad and publishes a monthly magazine. By 2004, the society was 6000 members strong.
(2) (Security ID) In Windows, a unique name assigned to each user and to each workgroup. See access token.
(3) (System ID) A unique number assigned to a wireless system. See NID.