Login is the action the user takes to authenticate and gain access to a desired application. SSO is a process that gives users the ability to access multiple protected resources (web pages and applications) with a single authentication. SSO is enabled by Access Manager to eliminate the need for additional or different logins to access other applications at the same (or lower) authentication level during the same session.
Access Manager enables administrators to create a web of trust in which a user's credentials are verified once and are provided to each application the user runs. Using these credentials, the application does not need to re-authenticate the user with its own mechanism.
Application SSO allows users who have been authenticated by Access Manager to access applications without being re-authenticated.