(Or "login", "log on", "loGon") To start a session with a system, usually by giving a user name and password as a means of user authentication. The term is also used to mean the ability to access a service (also called an account), e.g. "Have you been given a login yet?" "Log in/on" is occasionally misused to refer to starting a session where no authorisation is involved, or to access where there is no session involved. E.g. "Log on to our {Web site}!" "login" is also the Unix program which reads and verifies a user' s user name and password and starts an interactive session. To end a session is to "log out" or "off". (2004-11-16)