ARP is a protocol used for mapping an IP address. Address Resolution Protocol (ARP) translates a logical address into a physical address, where the former is Internet address and the latter is the Ethernet address. In a nutshell, ARP is a network protocol which is used to find the MAC address of a device from the given IP address.The device which wants to communicate sends an ARP request message containing the IP address of the destination device. All the locally connected devices can read the message, but only the device with the required IP address sends the reply containing its MAC address.