A packet switch is a device that routes data packets between computers in a network. It receives incoming packets, examines their destination addresses, and forwards them to the appropriate next hop. This process allows multiple data streams to share the same communication channel efficiently. Packet switches are essential components of the Internet and other networks, enabling the transfer of information without requiring a dedicated connection. They operate using protocols like TCP/IP, which help ensure that data is delivered accurately and in the correct order, even if packets take different paths to reach their destination.