P4D, the Perforce Server, manages the Perforce central file repository
(the "depot"), tracks Perforce user operations, and records activity
in the Perforce SCM database. You need one Perforce Server to
support all of the users in your enterprise.
P4 is a small, self-contained Perforce client program that offers
access to all Perforce SCM (software configuration management)
features through a command line. It can be used in command shells
and scripts, and is the ideal interface for automated processes
that perform SCM tasks.