Dial-up internet access, usually just called Dial-up, is a slow way of connecting to the Internet by using a telephone line. A modem is connected between a computer and a telephone line and then the modem is instructed to dial the phone number of an Internet service provider (ISP) to connect to the Internet. The ISP must be a dial-up service provider with several dial-up modems waiting to accept dial-up calls. This kind of internet is slower than DSL. It is not widely used in the United States, where only one out of every ten people still use it. In most parts of the world, the dial-up has been replaced by broadband.
Dial-up was the most common way of connecting to the internet from its creation until around the middle of the 2000s.