When a PAM aware privilege granting application is started, it activates its attachment to the PAM-API. This activation performs a number of tasks, the most important being the reading of the configuration file(s): /etc/pam.conf. Alternatively and preferably, the configuration can be set by individual configuration files located in a pam.d directory. The presence of this directory will cause Linux-PAM to ignore /etc/pam.conf. These files list the PAMs that will do the authentication tasks required by this service, and the appropriate behavior of the PAM-API in the event that individual PAMs fail.