Fragment

A piece of a packet. When a router is forwarding an IP packet to a network with a Maximum Transmission Unit smaller than the packet size, it is forced to break up that packet into multiple fragments. These fragments will be reassembled by the IP layer at the destination host. When a network receives a packet larger than its maximum allowable packet size, it breaks it up into two or more fragments. These fragments are each assigned a size (corresponding to the length of the fragment) and an offset (corresponding to the starting location of the fragment).