<security> (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.
The noun forms are usually written as a single word whereas
the verb forms are often written as two words.
