You must be familiar about the growing world of internet, now the internet works on the principle of IP addressing. An IP address is a long sequence of numbers which is provided to every host. This huge sequence of numbers is quite difficult to remember so what we do is that we use a concept of domain name system. This concept facilitates us to use the internet in a easy way.
A domain name system actually performs the mapping between the IP addresses and the domain names which are given to the hosts. A domain name is a sequence of labels separated by dots(.). Domain name can be classified as following:
Fully Qualified Domain Names: If a label is terminated by a null string, it is called a Fully Qualified Domain Name. It contains the full name of a host. It contains all labels, from the most specific to the most general, that uniquely define the name of a host, eg: kk.mm.ll.
Partially Qualified Domain Names: If a label is not terminated by a null string then it is called a Partially Qualified Domain Name. It doesn’t contain the full name of a host. It is used when the name to be resolved belongs to the same site as the client. For example, www is a partial domain name.
The sub tree of the domain name space is called domain. The name of the domain is the domain name of the node at the top of the sub tree. The domains can be further broken into sub domains. Some of the common domains are listed below:
Generic Domains: The generic domains define registered hosts according to their
behaviour. Each node in the tree defines a domain, which is an index to the domain name space database. For example: aero is used for airlines, com is used for commercial organizations.
Country Domains: These domains use two character country abbreviations. This domain is used specifically for a country. For example us is used for United States, the address can be anza.cup.ca.us.
The domain name system is a client-server application that identifies each host on the internet with a unique user-friendly name. This system organizes the name space in a hierarchical structure to decentralize the responsibilities involved in naming. So, what this system has done is that it has removed the overheads of writing the IP addresses again and again.
by Camila 1 year ago
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