What is the function of a modem?

A modem serves the crucial function of converting analog signals to digital signals, which enables communication over traditional telephone lines or other analog media. This process is vital for connecting to the Internet, as most Internet service providers (ISPs) send data in analog form. The modem translates these incoming analog signals into digital data that can be understood by computers and other digital devices. Conversely, when sending data out, it converts the digital signals from the devices back into analog form for transmission over the network.

For example, when a user connects their computer to the internet, the modem interacts with the ISP's infrastructure, ensuring that the data sent and received is in a format suitable for both the user’s devices and the ISP's transmission medium. This fundamental role of the modem is what enables reliable Internet access and communication.