How dsl modem act as router?

A DSL modem acts as a router by connecting to the internet service provider (ISP) through a DSL line and routing that internet connection to multiple devices within a local network. It does this by assigning local IP addresses to each connected device, enabling them to communicate with both each other and the internet. Additionally, the modem often includes built-in firewall capabilities to enhance security for the connected devices. Overall, it manages data traffic, ensuring efficient communication between the internet and local devices.