Answer Description
Dynamic Host Configuration Protocol (DHCP) assigns IP's to network devices. Domain Name Service (DNS) translates between IP Addresses and Domain names. Address Resolution Protocol translates between IP Addresses and MAC Addresses (Reverse-ARP, RARP does the opposite)
Wikipedia
The Dynamic Host Configuration Protocol (DHCP) is a network management protocol used on Internet Protocol (IP) local area networks A DHCP server must be present on the network A device connected to the network requests an IP address from the DHCP server using the DHCP protocol the server assigns a unique address to the device, identifying it for TCP/IP communication, and supplies other network configuration parameters In the absence of a DHCP server, a device that needs an IP address must be manually assigned a static address by a network administrator, or must assign itself an APIPA address (which will not enable it to communicate outside its local subnet)
Dynamic_Host_Configuration_Protocol - Wikipedia, the free encyclopedia