What does Hayes device do?

The Hayes device, commonly referred to as a Hayes modem, is a telecommunications device that allows computers to communicate over telephone lines. It uses a command set, known as the Hayes command set, to control the modem's functions, such as dialing phone numbers and configuring connection settings. This standard enabled easier and more standardized communication between computers and modems, facilitating the growth of online communication in the 1980s and 1990s.