ICANN stands for Internet Corporation for Assigned Names and Numbers. ICANN is a non-profit corporation located in Marina Del Rey, California tasked with managing the logistics of Internet Protocol (IP) addresses and domain names.
ICANN took over these duties previously served by the Internet Assigned Numbers Authority (IANA). ICANN has renewed its agreement in the month of September '2006 with the U.S. Department of Commerce (DOC) to continue in this capacity.ICANN's tasks include responsibility for Internet Protocol (IP) address space allocation, protocol identifier assignment, generic (gTLD) and country code (ccTLD) top-level domain name system management, and root server system management functions. More generically, ICANN is responsible for managing the assignment of domain names and IP addresses.
There are currently three Supporting Organizations for ICANN. The Generic Names Supporting Organization (GNSO) deals with policy making on generic top-level domains (gTLDs). The Country Code Names Supporting Organization (ccNSO) deals with policy making on country-code top-level domains (ccTLDs). The Address Supporting Organization (ASO) deals with policy making on IP addresses.
In addition to every computer online having a unique address, every website must also have a unique address. The domain name is only used as a convenience because names are easier for people to remember than a string of numbers, but each name maps back to a specific IP address. ICANN is thus a Registry that maintains the records of the domain names & the IP address.
In the Memorandum of Understanding that set up the relationship between ICANN and the U.S. government, ICANN was given a mandate requiring that it operate "in a bottom up, consensus driven, democratic manner."