ARP is a protocol used by the Internet Protocol (IP) [RFC826], to map IP network addresses to the hardware addresses used by a data link protocol. The protocol operates below the network layer as a part of the interface between the Open Systems Interconnection (OSI) network and OSI link layer. It is used when IPv4 is used over Ethernet.
The term address resolution refers to the process of finding an address of a computer in a network. The address is "resolved" using a protocol in which a piece of information is sent by a client process executing on the local computer to a server process executing on a remote computer. The information received by the server allows the server to uniquely identify the network system for which the address was required, and therefore to provide the required address. The address resolution procedure is completed when the client receives a response from the server containing the required address.
