TCP\IP under Windows NT allows a computer to communicate over a network with another computer by using either an IP address, a host name, or a NetBIOS name. However, when one computer attempts to communicate with another computer using one of these three naming conventions, that name must ultimately be resolved to a hardware address, the medium access control (MAC) address.
The Address Resolution Protocol (ARP) allows a host to find the MAC address of a destination host on the same physical network, given the destination host's IP address. To make ARP efficient, each computer caches IP-to-MAC address mappings to eliminate repetitive ARP broadcast requests.
The arp command allows a user to view and modify the ARP table entries on the local computer. The arp command is useful for viewing the ARP cache and resolving address resolution problems.