Every computer on a TCP/IP internetwork must be given a unique computer name and IP address. The IP address identifies both the computer and the subnetwork to which it is attached. When the computer is moved to a different subnetwork, the IP address must be changed to reflect the new subnetwork ID.
DHCP is designed to reduce the complexity of configuring computers for TCP/IP networks. RFC 1541 specifies two major components needed for DHCP services: a protocol for communicating TCP/IP configuration parameters between a DHCP server and a DHCP client, and a method for allocating IP addresses to the DHCP client.