Which device is essential for connecting a local network to the internet?

A router is essential for connecting a local network to the internet because it acts as a gateway that routes data between the internal network and external networks, including the internet. It manages traffic by determining the best paths for data packets to travel and ensures that data from the internet reaches the correct device within the local network. Additionally, routers often include features such as firewall protection and Network Address Translation (NAT), which enhance security and allow multiple devices to share a single public IP address efficiently.

In contrast, a switch functions primarily within a local network by connecting multiple devices and allowing them to communicate with each other. An access point expands wireless connectivity within a network but does not connect the network to the internet on its own. A repeater extends the range of a network signal rather than facilitating the actual connection to the internet. Each of these devices plays a role in networking, but it is the router that serves as the crucial link to the internet.