DSL modems, or Digital Subscriber Line modems, are devices that allow users to connect to the internet using a digital subscriber line (DSL) connection. DSL is a type of broadband internet connection that uses existing telephone lines to transmit data at high speeds. The modem converts the digital data from a computer or other device into a format that can be transmitted over the DSL connection, and vice versa. This allows users to access the internet and other online services through their DSL connection.