[2] JAAS was introduced as an extension library to the Java Platform, Standard Edition 1.3 and was integrated in version 1.4.
[1] JAAS has as its main goal the separation of concerns of user authentication so that they may be managed independently.
A login module is required to implement the javax.security.auth.spi.LoginModule interface, which specifies the following methods: Note: A Subject is the user that is attempting to log in.
Login modules are written by implementing this interface; they contain the actual code for authentication.
The login context is the core of the JAAS framework which kicks off the authentication process by creating a Subject.