What is the primary function of a modem in networking?

The primary function of a modem in networking is to convert analog signals to digital signals and vice versa. This process is essential for enabling communication between devices over telephone lines or cable systems, which typically transmit data in analog form. The modem acts as an intermediary that allows digital devices, such as computers and routers, to connect to the Internet by translating the digital data from these devices into a format that can be sent over the analog infrastructure, and conversely, translating the incoming analog signals back into digital form for the devices to understand.

This function is crucial for Internet connectivity, particularly in traditional broadband service, where data from a user's computer is transmitted over existing telephone lines or cable systems. Understanding the role of modems in this conversion process is fundamental to grasping how different types of internet connections work, such as DSL or cable internet.