Short for Dynamic Host Configuration Protocol,a communication protocol that dynamically or automatically assignsIP addresses to devices located on the network. With DHCP a devicecan have different IP address every time it connects to a network.DHCP also supports static and dynamic IP addresses on the samenetwork.

DHCP uses the concept of a "lease" or amount of time that a givenIP address will be valid for a computer. The lease time can varydepending on how long a user is likely to require the Internetconnection at a particular location. It´s especially usefulin education and other environments where users change frequently.Using very short leases, DHCP can dynamically reconfigure networksin which there are more computers than there are available IPaddresses.

Source - Techtarget.com