Point-to-Point Protocol - Definition from the Hotspot Shield Glossary
Point to Point or PPP is a protocol that provides a common method of transporting data between two directly connected computers (the points). This protocol is a very basic method of transportation and connectivity and is widely used in such mediums as mobile phones, telephone lines and broadband connections.
As Ethernet uses TCP and IP protocols, PPP was created for direct connections that didn’t include Ethernet. PPP works on the basis of data and link control, and protocol encapsulation - This is all handled after a connection has been established and the relevant configuration requests have been processed between the two devices. PPP is also known as RFC 1661.