A packet of data contains a packet header, payload, and trailer. The packet header includes the destination address, packet number, and originator’s address. Data is broken down into packets. Each packet could take a different route. A router controls the route a packet takes. Packets may arrive out of order. Once the last packet has arrived, packets are reordered. Including: serial, parallel, simplex, half-duplex, full-duplex. Including the advantages and disadvantages of each method. Including the benefits and drawbacks of the interface.