A network address is a component of the communication network and is associated with both hardware and software. The address is the means by which the sending node selects the receiving node for data transfer. It is also used by the receiving node to recognize what data is destined for it. An address is a unique code assigned to every node on a network. But an address is formed differently for different protocols. The length, position, and method used to specify an address are unique for each protocol. A communication node using one protocol cannot recognize the address of another protocol.