Before we can use Internet, we have to gain access to it. This access is achieved in one of numerous ways. Above all, the Internet is a collection of networks which are connected together through various protocols and hardware.
Dial-up Connection: One of the most common ways of connection to Internet is by dial up connection using a telephone line and a modem. Using these you can connect to a host machine on the Internet. Once connected telecommunications software allows you to communicate with the Internet host. When software runs it uses modem to place a telephone call to a modem that connects to a computer connected to the Internet.
The SLIP (Serial Line Internet Protocol) or PPP (Point to Point Protocol): two protocols; serial line interface protocol (SLIP) and the point-to-point protocol (PPP), allow a user to dial into the Internet. They convert normal telephone data stream into TCP/IP packets and send them to network. With these, user becomes a peer station on the Internet and has access to all of Internet's facilities.