The heart of TCP/IP is Internet Protocol (IP) addressing and routing. An IP address is a numeric identifier assigned to each device on an IP network. The IP address provides the location of the device on the network. IP addresses are logical addresses implemented in software, unlike MAC addresses. IP addresses are represented as binary numbers in four sets of 8 bits each, called an, in Internet Protocol Version 4 (IPv4). IPv4 addresses are logical 32-bit addresses, whereas IPv6 addresses are logical 128-bit addresses.