What is a domain name?
The main purpose of a domain name is to provide symbolic representations, i.e., recognizable names, to mostly numerically addressed Internet resources. This abstraction allows any resource (e.g., website) to be moved to a different physical location in the address topology of the network, globally or locally in an intranet, in effect changing the IP address. This translation from domain names to IP addresses (and vice versa) is accomplished with the global facilities of Domain Name System (DNS).
By allowing the use of unique alphabetical addresses instead of numeric ones, domain names allow Internet users to more easily find and communicate with web sites and any other IP-based communications services. The flexibility of the domain name system allows multiple IP addresses to be assigned to a single domain name, or multiple domain names to be services from a single IP address. This means that one server may have multiple roles (such as hosting multiple independent websites), or that one role can be spread among many servers. One IP address can also be assigned to several servers, as used in anycast networking.
The Top Level domains
Every domain name ends in a top-level domain (TLD) name, which is always either one of a small list of generic names (three or more characters), or a two-character territory code based on ISO-3166 (there are few exceptions and new codes are integrated case by case). Top-level domains are sometimes also called first-level domains.
The generic top-level domain (gTLD) extensions are:
Generic: .biz, .com, .info, .name, .net, .org, .pro
Sponsored: .aero, .asia, .cat, .coop, .edu, .gov, .int, .jobs, .mil, .mobi, .museum, .tel, .travel
Infrastructure: .arpa
Reserved: .example, .invalid, .localhost, .test
Pseudo: .bitnet, .csnet, .local, .root, .uucp, .onion, .exit
Second-level and lower level domains
Below the top-level domains in the domain name hierarchy are the second-level domain (SLD) names. These are the names directly to the left of .com, .net, and the other top-level domains. As an example, in the domain "global.register.org", "register" is the second-level domain.
Next are third-level domains, which are written immediately to the left of a second-level domain. There can be fourth- and fifth-level domains, and so on, with virtually no limitation. An example of a working domain with four domain levels is www.sos.state.oh.us. The www preceding the domains is a host name of the World-Wide Web server. Each level is separated by a dot, or period symbol.
Official assignment
The Internet Corporation for Assigned Names and Numbers (ICANN) has overall responsibility for managing the DNS. It administers the root domain, delegating control over each TLD to a domain name registry. For ccTLDs, the domain registry is typically installed by the government of that country. ICANN has a consultation role in these domain registries but cannot regulate the terms and conditions of how domain names are delegated in each of the country-level domain registries. On the other hand, the generic top-level domains (gTLDs) are governed directly under ICANN, which means all terms and conditions are defined by ICANN with the cooperation of each gTLD registry.
What characters allowed in a Domain Name?
Domain names are restricted to the ASCII letters "a" through "z" (case-insensitive), the digits "0" through "9", and the hyphen "-", Most names end in the above top level domains, of which .com is the most popular. They cannot begin or end with a dash, and no space is allowed before, between, and after your domain. You can have up to 67 characters now (include the top level domain) in order to increase search engine placement. However, some web browsers may not be compatible with names longer than 58 characters. Try to keep it below that length for greater compatibility.
Domain names are often referred to simply as "domains" and domain name registrants are frequently referred to as "domain owners", although domain name registration with a registrar does not confer any legal ownership of the name, only an exclusive right of use.
Why Should I get a Domain Name?
There are many reasons why you should get a domain name.
Even though you may not need one this second, it is always wise to secure one if you are company that has registered trademarks or brand names. If you don't really have a purpose or idea for the Internet at the present time, your domain name may stand idle for some time, but when you finally have the resources to start something on the Internet, the domain name that you have chosen will be available right away.
There are currently over 32 million domain names registered today. Thousands more are being registered each day. There is a scarcity of the above top level domain names that now they are planning to move on to other top level domains, such as .biz, .info, .museum, etc. Some of these are endings specified for specific industry, category of people/business. You may not be able to register for them if you are not qualified. Many of these names are also being pre-registered already. They will be snatched up immediately once available.
If you do a search for something that you are interested in, you will find that it takes you quite a while to come up with a domain name that satisfies you. Almost all of the three, four and five letter English words are gone. Of the 3 letter and number combination, the only domains available are names such as 33A.com and other undesirable combinations. If you do get a domain name like theme.com, which my friend owns, it is potentially worth hundreds of thousands of dollars.
Your Own Website
It seems that everyone has a website these days. You may not have the slightest idea on how to go about building a website, but if you can work the Internet and a word processor, you can probably build a website. There are many different tools and automated programs to help you do this. There are a lot of online resources, such as free graphics, ideas, dynamic programs that can make your site pleasing to the eye and also interactive with your visitors.
You could obtain a name based on your name. For example, if you are a medical doctor, you could register your domain as dryourname.com or doctoryourname.com. If you have an uncommon name, most probably it is still available.
You could also register a name based on your interests. If you make a site on the TV show Friends, it would be something that interests you and gives you some motivation to express your ideas and opinions etc.
Branding with a domain name
Brands are greatly affected by the ability of the company to obtain the matching domain name. If a company builds a brand around a name to which it does not own the domain name, it can end up directing traffic to another domain owner's site. If it is a competitor, this would be a problem.
Today's advertising development of a great brand is strictly confined to the availability to synchronize the brand with a domain name. Any confusion might result in a competitor gaining valuable internet traffic and possible customers.