| user identifier 1. (Or "uid", "user id") A number or name which is unique to a particular user of a computer or group of computers which share user information. The uses the uid to represent the user in its data structures, e.g. the owner of a file or process, the person attempting to access a system resource etc. A user database, e.g. 's /etc/passwd file or , maps the uid to other information about that user such as their , , and real name. 2. . (1997-03-01) |