PPTP stands for Point-to-Point Tunneling Protocol, which is a method for implementing virtual private networks (VPNs) . It is one of the oldest VPN protocols still in use, having been around since Windows 95 and standard on all versions of Windows since. PPTP uses a TCP control channel and a Generic Routing Encapsulation tunnel to encapsulate PPP packets. It is easy to set up and computationally fast, making it useful for applications in which speed is paramount, like audio or video streaming, and on older, slower devices with more limited processors. However, PPTP is also subject to serious security vulnerabilities, and its underlying authentication protocols are fundamentally unsecure and have been repeatedly cracked in security analyses since PPTP was introduced. For this reason, PPTP is not recommended except in cases where security is absolutely non-essential, and it is not supported by some VPN apps.