PAMs provide a system for abstracting authentication and authorization technologies. With a PAM module, it is possible to specify different authentication methods for different system applications without having to recompile these applications. PAM is also useful for implementing a particular policy for authorization. For example, a system administrator may only allow console logins from users stored in the local password file but only allow users resolved from an NIS database to log in over the network.

Winbind uses the authentication management and password management PAM interface to integrate Windows NT users into a UNIX system. This allows Windows NT users to log in to a UNIX machine and be authenticated against a suitable PDC. These users can also change their passwords and have this change take effect directly on the PDC.

PAM is configured by providing control files in the directory /etc/pam.d/ for each of the services that require authentication. When an authentication request is made by an application, the PAM code in the C library looks up this control file to determine what modules to load to do the authentication check and in what order. This interface makes adding a new authentication service for Winbind very easy: simply copy the pam_winbind.so module to /lib/security/, and the PAM control files for relevant services are updated to allow authentication via Winbind. See the PAM documentation in PAM-Based Distributed Authentication, for more information.