When you type google.com into your browser, the domain is split into parts by the “dot”, from right to left. The first part is “com”, so your computer checks the root zone file to see which registry manages the .com TLD. It then checks with this registry to see where the next part, “google”, points to. The registry returns the IP address 22.214.171.124, and your computer can then ask Google to send their homepage over.
The practice of using a simple memorable abstraction of a host's numerical address on a computer network dates back to the ARPANET era, before the advent of today's commercial Internet. In the early network, each computer on the network retrieved the hosts file (host.txt) from a computer at SRI (now SRI International), which mapped computer host names to numerical addresses. The rapid growth of the network made it impossible to maintain a centrally organized hostname registry and in 1983 the Domain Name System was introduced on the ARPANET and published by the Internet Engineering Task Force as RFC 882 and RFC 883.
My personal preference is to register the name directly with a domain name registrar rather than through my web host. I've heard stories, in the past, of less-than-reputable web hosts that registered the domain under their own name, making them the owner of the domain rather than you (although I don't know if such web hosts still exist today). Registering direct with a domain name registrar allows me to make sure that I am registered as the owner, the administrative and technical contacts. Being the owner is vital — if someone else places himself as the owner (such as your web host), he can always decide to charge you some exorbitant fee for the use of the name later, and there is little you can do. The various other contacts are less vital, but may still play important roles, depending on your registrar. For example, for some registrars, the administrative contact's approval is required before a domain name is transferred out of a web host (or at least, it used to be). If he/she cannot be contacted, the technical contact is used.
A domain name is, quite simply, the name of your website. The domain can be found in the URL and is used in order to locate the website of a specific person or organization. Each domain name or URL directs users to a specific IP address. Domains are easier to remember than a long and complicated IP address, which takes the form of a series of numbers. A domain can be divided up into three different elements: a subdomain, a domain name, and a top level domain (TLD). Take about.1and1.com as an example: the 'about' element is the subdomain, the '1and1' element is the domain name itself and the '.com' part of the URL is the top level domain. It is also possible to have multiple subdomain levels, info.about.1and1.com for example, which you can use to segment your website into separate categories. The length limit of a complete domain name is 255 characters. With 1&1, you can choose a domain name that best suits you or your business, or you can transfer an already existing domain over to 1&1. Next, customers can select a TLD from a wide variety of domain extensions on offer. When choosing a domain name, it is important to select something that properly reflects the ethos of your business in a concise and catchy way. A good domain should be memorable, brandable, and should have a suitable extension.
Second-level (or lower-level, depending on the established parent hierarchy) domain names are often created based on the name of a company (e.g., bbc.co.uk), product or service (e.g. hotmail.com). Below these levels, the next domain name component has been used to designate a particular host server. Therefore, ftp.example.com might be an FTP server, www.example.com would be a World Wide Web server, and mail.example.com could be an email server, each intended to perform only the implied function. Modern technology allows multiple physical servers with either different (cf. load balancing) or even identical addresses (cf. anycast) to serve a single hostname or domain name, or multiple domain names to be served by a single computer. The latter is very popular in Web hosting service centers, where service providers host the websites of many organizations on just a few servers.
A domain name registration is simply reserving your website's name for a specified period of time. The two parties involved with a domain registration are generally the user who is registering the domain and the domain registrar. The domain registrant is the user who actually registers the domain name and the domain registrar is the company who helps that user with their domain registration.
Domain names were created to make IP addresses easy to remember. Every computer has an IP address assigned to it – much like a street address. But instead of having to memorize each IP address number, we assign domain names to these numbers so we can easily remember them. The domain name system, or DNS, takes domain names and translates them into their IP addresses so that computers can communicate with one another. When you enter a domain name into your web browser, the browser simply uses that domain to locate its corresponding IP address and then shows you the website associated with it. If you own a business, GoDaddy can help you find a domain name that best suits the business so you can easily promote your website.
An important function of domain names is to provide easily recognizable and memorizable names to numerically addressed Internet resources. This abstraction allows any resource to be moved to a different physical location in the address topology of the network, globally or locally in an intranet. Such a move usually requires changing the IP address of a resource and the corresponding translation of this IP address to and from its domain name.