A router and a modem are two devices that are essential for connecting to the internet. While they both have the same goal of connecting a network to the internet, they do so in different ways. A router connects multiple computers, phones, or other devices together within a single network, while a modem connects the network to the internet.

A router is responsible for connecting the devices within the network to one another, allowing them to communicate and share resources. It also acts as a firewall, preventing unwanted visitors from accessing the network. A modem, on the other hand, connects the network to the internet service provider. It does this by translating the signals from the ISP into a format that the router and the devices on the network can understand.