|  | 11.1 | Routing Basics
| 11.1.4 | Path selection and packet switching
A router generally relays a packet from one data link to another, using two basic functions: a path determination function a switching function. Figure illustrates how routers use addressing for these routing and switching functions. The router uses the network portion of the address to make path selections to pass the packet to the next router along the path. The switching function allows a router to accept a packet on one interface and forward it through a second interface. The path determination function enables the router to select the most appropriate interface for forwarding a packet. The node portion of the address is used by the final router (the router connected to the destination network) to deliver the packet to the correct host.