DHCP - Dynamic Host Control Protocol.
DHCP is a method of assigning IP (network) addresses automatically. In most network environments, this task is handled by the router/firewall. In a client/server environment, this task may be handled by the Windows Server operating system. Every computer on the network must have a unique address. If you must assign static addressing to any system (say for credit card processing), you must assure that the assigned address is not in the IP address pool. Click here for detailed instructions.