Devices in a home network connect to a router, which connects to an Internet service provider (ISP) to access the Internet. The ISP might connect to a larger ISP before connecting to a fiber-optic "backbone" serving an entire nation or region. To access a Web server—for example, to read a news story on the BBC website—data would travel from a device on the home network across numerous other devices to reach its destination: the BBC webserver.
Multiple devices on the home network can send and receive data while our device accesses the BBC webserver. These independent data traffic streams intersect at the home broadband router. The router has several input ports that allow multiple devices to send data outside of the home network to the Internet. Data packets are transmitted from output ports on a router. Typically, a home broadband router has one output port that connects a line to an ISP.