ICANN is the agency which coordinates the internet's IP addressing and DNS systems.
ICANN stands for Internet Corporation for Assigned Names and Numbers. Aside from coordinating the Domain Name System (DNS) and Internet Protocol (IP) addresses, it also coordinates the technical protocol parameters of ARPA top level domain, Internet DNS root zone management (gTLD and ccTLD), allocates Internet number resources, and other services which will fulfill their vision of "one world, one Internet".
The performance of ICAANs services is all under a U.S Government contract.