All you need to know about Domain Names
Published: Mar 17, 2010
The definition of DNS (Domain Name System) can be understood as a structured and hierarchical mode of naming, developed for naming computers, systems and other resources connected to the web, or any similar network. Not only does it help users in browsing different websites on the web, but also in locating and addressing a multitude of devices across the globe. All computers on the web have exclusive addresses which are in the form of numbers separated by dots, called "IP address" (Internet Protocol).
The human memory finds it not easy to remember a string of numbers without any correlation as to the definition of the content of these numbers or the representation of these numbers. Therefore the DNS helps the users to remember domain names or addresses associated with the websites or people rather than the IP addresses by which they are tagged. For instance, 220.127.116.11 makes absolutely no sense to the common Internet user, whereas the Google website (www.google.com) is more significant to them. All that the users need to do is to enter the domain title instead of the IP address, and it takes them to the specific website. Converting the domain name to the corresponding IP address is termed as "resolving the domain". Further, domain names and addresses are used for denoting email addresses and alternate web applications.
Significance of the Domain Name System as a telephone directory
The DNS and the domain addresses of websites can be compared with telephone numbers that are unique; they can refer to a single website or a destination point globally. Anybody across the world can reach it if it is accessible universally. The domain name associated with a given IP address is unique and therefore acts as a pointer to the specific webpage, saving a lot of time, memory and ambiguity. The exclusivity and reliability of the IP address to point to one single website makes it analogous to a phone number. There is an important term called "Universal resolvability" associated with the DNS which ensures positive results across the globe on the web. The resourcefulness and the design structure of the Domain Name System make the Internet useful to send and receive emails. It is also to be understood that the IP address associated with each domain name is not dependent on the physical location of the system or the server.
How ICANN fits in the scene
ICANN, the global, private-sector body is also a non-profit organization that ensures efficient functioning of DNS. It achieves the purpose by efficient supervision of the tagging of unique Internet Protocol addresses and the associated domain names. The whole process of managing the systems and processes that map the IP addresses to their domain names to make sure worldwide resolvability is done by this governing body. To understand this concept and what ICANN does, it is necessary for you to consider this body as a giant router or a switch which aims at directing signals to the desired destination. The other tasks of ICANN include IP address space allocation, generic and country-code TLD management and root server system management functions. Further it also has to ensure global participation from all continents in the world to achieve its purpose. The mission of ICANN, as clearly paraphrased, is to "protect and preserve the stability, integrity and utility of the global Internet community, the DNS and the authoritative root ICANN was actually established to manage".
Mechanism behind the arena
The conventional Internet addresses such as google.com has different parts - the .com part can be referred to as the High Level Domain, or else the TLD; there are specific registries called the "TLD registry" that contains online databases housing information about a list of names of domain in that specific TLD. For instance, the .com registry database contains information about the domain name "google.com". Therefore, to find out the Internet address of google.com, the computer initially searches the .com registry database. To better aid your understanding let us consider the .org domain of which icann.org is a part of. This being the case, www.icann.org is a sub domain of the domain icann.org, which signifies that the hyperlinked URL is a World Wide Web page. This subdivision can go down to 127 steps or lesser, depending on the TLD.
To understand how the Domain Name System operates, it is important to understand that the epicenter of the DNS has 13 root servers, harmonized by ICANN moreover distributed across the planet. The root servers have the identical significant information, which aids in spreading the workload while serving as a backup for each other. The main servers contain information pertaining to the Internet protocol addresses of every TLD registry, further divided into the global static registries like .com, and .net, and region-specific registries like .in (India). Without this critical information, it would not be feasible to trace the domain names across the world. Therefore, it has to be authentic and unique.
What part do DNRs play?
There are several computers broaden across the world with the sole purpose of translating the domain names into IP addresses. They aid in directing the queries of the user to the specific website and are termed as "Domain Name Resolvers", sometimes-just "resolvers". They also index the information and store the queries in the main servers. It is to be understood that these special computers are located with all the ISP and the organizational networks. The way they operate is that they accept the user's query in the form of a domain name, look it up on their registry and direct the user to the specific website. The main function of these resolvers is to understand the user's query irrespective of whether it is a recursive or a non-recursive query and translate it into an IP address.
The path of the user's request
After a person enters the domain name in his browser, it is accepted as a request and is first frontward to a limited DNS resolver, where the domain name query is split into its constituent parts. With the TLD, the resolver discovers the .com registry from where it is forwarded to the .com registry and the Internet protocol address corresponding to the website google.com is the output of the query. The output, in the form of an IP address, can be forwarded to the user's computer. This establishes that one IP address can correspond to one website or domain name only. There cannot be multiple TLDs of a single name, which would otherwise create ambiguity.
The questions as to why the resolvers are needed and how they can be an aid to slow down the browsing process are analyzed; the reason why resolvers are necessary is for their performance. They are capable of handling a huge number of requests at one time and they need extensive storage space for their data and indexing.