What is slip/ppp in computer networking ?

Point to Point protocol (PPP) is used to link data in the networking points, it provide the authentication to the network and it is also very secure and provide anonymous authentication. Most of the internet provider use PPP to provide network connection on the home network and Serial line IP (SLIP) is used to work over modems but now a days it is replaced by PPP in the home computers or you can say that SLIP is the older form of PPP.
Yes PPP is only responsible for dial up connection .