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.
PPTP technology extends the Point to Point Protocol (PPP) standard for traditional dial-up networking. PPTP operates at Layer 2 of the OSI model. As a network protocol, PPTP is best suited for the remote access applications of VPNs, but it also supports LAN internetworking.