In the beginning, all internet addresses ended in .com. In an Internet address-such as OttEsq.com - the .com part is known as a Top Level Domain, or TLD. As the number of addresses grew, so did the need for more TLD's.
So-called "TLD registry" organizations house online databases that contain information about the domain names in that TLD. The .com registry database, for example, contains the Internet whereabouts - or IP address - of OttEsq.com. In trying to find the Internet address OttEsq.com, your computer must first find the .com registry database.
At the heart of the DNS are 13 special computers, called root servers. They are coordinated by ICANN and are distributed around the world. All 13 contain the same vital information - this is to spread the workload and back each other up.
The root servers contain the IP addresses of all the TLD registries - both the global registries such as .com, .org, etc. and the 244 country-specific registries such as .fr (France), .cn (China), etc. This is critical information. If the information is not 100% correct or ambiguous, it might not be possible to locate a key registry on the Internet. In DNS parlance, the information must be unique and authentic.
Scattered across the Internet are thousands of computers, called "Domain Name Resolvers". They routinely download and copy the information contained in the root servers. Resolvers are needed for performance reasons. Root servers cannot handle the hundreds of billions of requests a day. Resolvers are located strategically with Internet Service Providers (ISPs) or institutional networks. They are used to respond to a user's request to resolve a domain name - that is, to find the corresponding IP address.
When a user requests to reach any particular site, the request is forwarded to a local resolver. The resolver splits the request into its component parts. First, the resolver finds the IP address for the .com registry, queries that registry to find the IP address for OttEsq.com, then queries a local computer at that address to find the final IP address for www.OttEsq.com. This answer is forwarded back to the user's computer.
ICANN is a consensus development body for the global Internet community, and its focus is the development of consensus policies relating to the single authoritative root and the DNS. These policies include those that allow the orderly introduction of new TLDs. In light of the recent internet growth, ICANN is working to add new TLDs to the Internet's domain name system. For more info on these new TLDs, see Fun Fact column at left.