The way messages get transmitted by protocols is in the form of packets. A packet is a group of bytes that are transmitted as a unit in a specific order. Some of the bytes are the source address, destination address, and control codes for the message, others are the data being sent. The rules governing the order of the bytes allows the sender and receiver to make sense of the message. Sometimes, a packet will be included inside another packet as data, a process known as encapsulation. For example, a Netware IPX packet is encapsulated in an Ethernet packet when the Netware network is running on Ethernet, but the same packet gets put inside a Token-ring packet in a Netware token-ring network.