A router forms part of an internet network by allowing all the devices in a building to connect to the internet. A modem brings the internet service from your provider into your home or office. This data is then sent to a router which forwards the internet connection to all your WiFi devices such as laptops and smartphones. This internet connection consists of data packets such as e-mails or web pages which contain an IP network address telling the router the end destination of the data. Routers in homes and small offices simply forward IP packets between home computers and the internet. Large businesses have more powerful and complex enterprise routers designed to send data over larger geographical areas called WANs (Wide Area Network) so data packets may need to be passed between several routers until it reaches its final IP destination