Point-to-Point Protocol.
PPP is a communications protocol used to transmit network data over telephone lines. It allows you to connect your computer to the Internet itself, rather than logging on through an Internet Service Provider's host computer and using UNIX commands through a shell. This type of connection lets you communicate directly with other computers on the network using TCP/IP connections. It is part of the TCP/IP suite of programs necessary to connect to and use the Internet.

If you have a dial-up account with an Internet Service Provider, you are using either PPP or SLIP to make your connection to the Internet. PPP (Point-to-Point Protocol) is rapidly replacing SLIP (Serial Line Internet Protocol) as the more common standard. Where as SLIP is easy to install and to use, it does not provide error correction or certain negotiation features that are built into PPP.

Where do you get PPP? If you bought an Internet package, a PPP program would be part of the collection of software programs you received. Some Internet Service Providers will give you a disk with the appropriate software when you sign up for an account. Others will point you to a BBS where you can download the software yourself.