DNS | Domain Name System | Internet Fundamentals

Domain Name System (DNS)

In order to understand DNS, we need to have a basic understanding of IP addresses and domain names. An IP address is a string of numbers that acts as an identifier for devices across the Internet. In short, an IP address is the address that computers, servers and routers used to identify one another online. The vast majority of IP addresses are arranged into four sets of digits – i.e., 12.34.56.78.

DNS = Domain Name System

DNS = Domain Name Server

DNS = Domain Name Service

DNS translates domain names into IP addresses. Because domain names are alphabetic, they’re easier to remember. But Internet is really based on IP addresses. Every time you type a domain name into address bar of browser window, DNS service must translate the name into the corresponding IP address. For example, the domain name www.google.com would translate to 74.125.224.72.

Remembering www.google.com would be easier than remembering 74.125.224.72. Human beings can remember names easily than numbers.

A domain name is the information that you enter into address bar of a browser in order to reach a specific website. When you input a URL like www.google.com into a web browser, its domain name is google.com. Basically, a domain name is the human-friendly version of an IP address.  Note that names are easier to remember than numbers.

The DNS translates domain names to IP addresses. DNS automatically converts the names into IP addresses of web servers hosting those sites.

Domain Name

A domain name is a unique name that identifies a website. Each website has a domain name that is used to access that website. No two organizations can have the same domain name. Mobile number is unique in the world. No two persons can have same mobile number. The same way no two organizations can have same domain name.

Whenever you visit a website, the domain name appears in the address bar of the web browser. All domain names have a domain suffix, such as .com, .net, or .org. Suffix identifies the type of website. For example, “.com” domain names are used by commercial website, while “.org” websites are used by non-profit organizations. Some domain names end with a country code, such as “.dk” (Denmark) or “.se” (Sweden), which helps identify the location and audience of the website.

Major domain addresses

NOTE: When you access a website, the domain name is actually translated to an IP address. This translation is performed by a service called DNS.

NOTE: Domain names must be registered in the beginning and renewed every year or every few years. Note that anyone can register a domain name with nominal fee. Once you decide a domain name and register it, the name is yours until you stop renewing it. When the renewal period expires, the domain name becomes available for others to purchase.

NOTE: Without DNS, we would have to remember the IP address of every web site we wanted to visit. The reason the Domain Name System is used is because Web sites are actually identified by their IP addresses. For example, when you type in http://www.adobe.com, the computer doesn’t immediately know that it should look for Adobe’s Web site. Instead, it sends a request to the nearest DNS server, which finds the correct IP address for “adobe.com.”