Explain what each line is doing is this /etc/pam.d for the login service

auth optional pam_faildelay.so delay=3000000 auth [success=ok new_authtok_reqd=ok ignore=ignore user_unknown=bad default=die] pam_securetty.so auth requisite pam_nologin.so session [success=ok ignore=ignore module_unknown=ignore default=bad] pam_selinux.so close session required pam_env.so readenv=1 session required pam_env.so readenv=1 envfile=/etc/default/locale @include common-auth auth optional pam_group.so session required pam_limits.so session optional pam_lastlog.so session optional pam_exec.so type=open_session stdout /bin/uname -snrvm session optional pam_motd.so session optional pam_mail.so standard session required pam_loginuid.so @include common-account @include common-session @include common-password session [success=ok ignore=ignore module_unknown=ignore default=bad] pam_selinux.so open