A temporary connection between machines

Internetworking Dictionary A temporary, as opposed to dedicated, connection between machines established over a standard phone line.

is the old way to use the internet, where you had to connect to the internet when you wanted to use it. Nowadays, most people use broadband.

The ability to dial-up the Internet (at speeds up to 56Kbps) through a modem using a standard telephone line.

A temporary connection between machines established with modems over a standard phone line.

An early kind of internet connection, using a phone line and a modem. Much slower than broadband, it has to make a phone call to the server and establish a connection before you can use it.

Dial-up networking (switched services) refer to transmission provided over a network of nondedicated lines. A switched connection is a temporary transmission path created when needed, and then released. Basic telephone service is an example of a dial-up network.