With a router you can connect networks. Most people will use a router to connect their local (wireless) home or office network (LAN) with the Internet. The router makes sure that all computers on the local network can connect with one another, with shared resources and with the Internet and can be configured to forward requests for connections from computers on the internet to the appropriate local computer. In order to connect your local network to the internet via an ADSL or cable, you also need an (Ethernet) ADSL or cable modem if it is not built-in in the router, which is most likely to be the case.