Definition: PPTP is a network protocol used in the implementation of Virtual Private Networks (VPN). RFC 2637 is the PPTP technical specification.
PPTP works on a client server model. PPTP clients are included by default in Microsoft Windows and also available for both Linux and Mac OS X. Newer VPN technologies like L2TP and IPsec may replace PPTP someday, but PPTP remains a popular network protocol especially on Windows computers.