Domain Name System (DNS)
Domain Name System is a system that matches the Domain Names with the IP addresses. Let us elaborate this beginning with the two keywords- Domain Name and IP Address.
Whenever your computer gets connected to the Internet, it is assigned an Internet Protocol (IP) Address by the ISP. It serves to identify and locate your machine. It is in numerical form such as 220.127.116.117 according to the format set by the Internet Protocol.
Different IP addresses may be assigned for a single machine for different sessions but it is unique for each connected machine at any point of time. There are also static(i.e. not changing) IP addresses which can be allotted for special needs such as for web servers.
Domain name is a unique name assigned to a website and it is used by the end users to communicate with it. It consists of several labels separated by (.) mark. The rightmost label represents the top level domain (TLD) which may be generic TLD such as .com, .net, .org or country code TLD such as .uk, .de, .fr for United Kingdom, Germany (Deutschland), France respectively. The label left to TLD represents its subdomain and so on.
In most cases, you will find three labels such as in www.example.com. Here com is the TLD and example is the sub domain of it which is the unique name chosen by the website owner from among the available(i.e. not chosen by some other person) domain names under a particular TLD. The www represents the server which is World Wide Web server in our case and may be mail or ftp servers in others.
Domain Name System
An IP address is a sequence of numbers which is difficult to remember. So it is cumbersome for us to remember numerous IP addresses and then use them directly to interact with different websites. On the other hand, domain name, though easy for us to remember is but unfeasible for telecommunication purposes. It is very complex to work with string of characters in communication systems rather than with usual binary numbers.
What can be the solution for this?
To solve this problem a directory was needed that matches the domain names to be typed by users with the IP addresses of the requested servers . Domain Name System (DNS) is that very provision. It is a globally distributed directory service that maps the domain names with the IP addresses of the respective servers. It is maintained by several organizations and even by individuals who can afford to.
In this way, we are relieved of maintaining a directory of domain names and IP addresses in order to use the internet as we still do in case of phone directory.
Whenever a new registration of domain name happens, it is added to the so called whois database and DNS server is updated. It is also updated when the IP address of the web server changes. Thus it is continuously getting upgraded and overhauled.
Registering a Domain Name
Do you want to own a website? Then the first thing you need to do is to register a domain name for it. The authority responsible for assignment of domain names is Internet Corporation for Assigned Names and Numbers (ICANN). Rather than assigning directly, it authorises individual or organisational entities as Domain Name Registrars to assign domain names to individual registrants.
There are several registrars in the market providing the service of domain name registration. They will charge you to register your domain name for a period of one or more years and to re-register it thereafter.
Technically, you may choose a domain name arbitrarily so long it has not been chosen by someone before. Good domain names are meaningful, easy to remember & type, brandable and probably related to the website content. While doing so, keep in mind the impression it makes upon the user and also that it is significant from Search Engine’s (SEO) viewpoint.