Which device is essential for connecting a LAN to the internet?

A router is essential for connecting a Local Area Network (LAN) to the internet because it serves as the gateway between the local network and external networks, such as the internet. The router manages traffic between the devices on the LAN and ensures that data is sent to the appropriate destinations both within and outside the local network.

Additionally, routers typically include features such as Network Address Translation (NAT), which allows multiple devices on a LAN to share a single public IP address when accessing the internet. This is vital for managing connections and maintaining security within the LAN while facilitating internet access.

While other devices play important roles within a network, they do not provide the full functionality needed to connect a LAN directly to the internet. For example, a modem connects to an internet service provider and provides access to the internet, but it requires a router to manage the internal network and distribute the internet connection to multiple devices on the LAN. A wireless access point (WAP) allows wireless devices to connect to the network, but it also needs a router to facilitate a connection to the internet. A network switch connects devices within a LAN but does not provide internet connectivity. Thus, a router is the key device necessary for linking a LAN to the internet effectively.