Dial-up refers to an Internet connection that is established using a modem. The modem connects the computer to standard phone lines, which serve as the data transfer medium. When a user initiates a dial-up connection, the modem dials a phone number of an Internet Service Provider (ISP) that is designated to receive dial-up calls. The ISP then establishes the connection, which usually takes about ten seconds and is accompanied by several beeping an buzzing sounds.
After the dial-up connection has been established, it is active until the user disconnects from the ISP. Typically, this is done by selecting the "Disconnect" option using the ISP's software or a modem utility program. However, if a dial-up connection is interrupted by an incoming phone call or someone picking up a phone in the house, the service may also be disconnected.
In the early years of the Internet, especially in the 1990s, a dial-up connection was the standard way to connect to the Internet. Companies like AOL, Prodigy, and Earthlink offered dial-up service across the U.S., while several smaller companies offered local dial-up Internet connections. However, due to slow speeds (a maximum of 56 Kbps), and the hassle of constantly disconnecting and reconnecting to the ISP, dial-up service was eventually replaced by DSL and cable modem connections. Both DSL and cable lines, known as "broadband" connections, offer speeds that are over 100 times faster than dial-up and provide an "always on" connection. While we don't get to listen to the fun buzzing and beeping noises of older modems anymore, it certainly is nice to download data in a fraction of the time.