What is the primary function of a modem in a cable internet setup?

The primary function of a modem in a cable internet setup is to convert digital data from a computer into analog signals suitable for transmission over the cable network, and then to convert incoming analog signals back into digital data for the computer. This conversion is essential because data transmitted over cable lines must be in an analog format, while most user devices, such as computers, operate digitally. The modem acts as a bridge between the digital world of the device and the analog world of the cable infrastructure, enabling seamless communication and internet access. This foundational role is critical for establishing a reliable internet connection.

In contrast, amplifying signals focuses on enhancing signal strength rather than facilitating data conversion, routing signals pertains to directing traffic across a network which is typically done by routers rather than modems, and providing Wi-Fi connectivity is the responsibility of a router or a combined modem/router device but is not a primary function of the modem itself.