The DHCP protocol enables host systems in a TCP/IP network to be configured automatically for the network as they boot. DHCP uses a client/server mechanism. Servers store and manage configuration information for clients, and provide that information upon a client's request. The information includes the client's IP address and information about network services available to the client.
DHCP evolved from an earlier protocol, BOOTP, which was designed for booting over a TCP/IP network. DHCP uses the same format as BOOTP for messages between client and sever, but includes more information in the messages. The additional information is the network configuration data for the client.
A primary benefit of DHCP is its ability to manage IP address assignments through leasing, which allows IP addresses to be reclaimed when not in use and reassigned to other clients. This enables a site to use a smaller pool of IP address than would be needed if all clients were assigned a permanent address.