What is DNS Server and How Does it Work?
What is DNS Server? DNS stands for Domain Name System. This is actually a service that runs on all of our computers but majorly it runs the entire internet. We type a website in the browser and with the bling of our eyes the website is open. Have you ever wondered how does that happen? In today’s article, we will learn the process of how the website opens so fast and how DNS plays an important role in this process.
We already know that every website is saved in a server that is located somewhere in the world. We need to reach this server and ask for the website homepage. In order to reach this Server, we need the address. When we want to visit a person in real life, we need his home address but in the world of the internet, we need the logical address. Internet Protocol, also known as IP Address is the logical addressing system.
In order to reach a website we need to enter its server IP in the browser and the server will reply with the homepage. Initially, when the internet was in its infancy, people kept the record of IP addresses. Gradually, the internet because huge, and keeping the record of IP addresses was a challenge. The markers of the Internet knew that humans are very good at remembering names than numbers. They came up with the idea of a DNS Server.
What is DNS Server?
DNS server is a kind of server. This server keeps the records of the domain name with its IP Addresses. A domain name is a simplified name that humans can remember easily, Such as Facebook.com. Our network devices don’t understand the domain names, they understand logical addresses (IP Addresses). The computer scientists came up with the idea of transferring the responsibility to remember the IP Addresses to somebody else.
They designed a special kind of server that could keep the record of domain names with their IP addresses. Just like the contact list on our phone. The scientists designed the DNS server to provide us the IP Address when we give it the Domain name. For instance, if we give it www.google.com it will return its IP Address of www.google.com. The number of websites kept growing and the type of DNS servers also increased. These servers are designed cleverly so that they can give us the result as quickly as possible.
Look at the picture above, I have designed this to explain the process of how does a website open on our computer screen. The internet became huge in a very short span of time. The websites increased and the types of domains also increased.
Governments started creating their websites, they wanted a different type of domain. They went for the .gov. For example https://www.usa.gov. This became the identity of the website. Anyone could recognize the website ends with .gov so it will be a government website.
Some websites were designed to provide Education. Educationists took the .edu. Other websites were to provide just some information to so they went for the .info.
The scientists knew we needed a hierarchy of DNS servers so they can give us the result in the shortest time possible. So they came up with ROOT DNS, Top Level DNS and Authoritative DNS.
ROOT DNS Server
When we enter the website in the browser, first of all, the IP is responsible to provide the IP address for the website. In order to do that, ISPs keep their own local DNS server. If any website IP is not available in the record of the Local DNS Server then the query goes to ROOT DNS.
Thirteen root servers are available worldwide to provide server. These root servers do not keep the IP addresses of the website but they keep the IP Addresses of the servers that keep the IP addresses of specific types of Servers. For example, if somebody asked for the IP of www.usa.gov, the root server will give the IP address of Top Level DNS.
Top Level DNS Server
The TOP Level DNS also does not maintain the address of real websites, It maintains the IP addresses of Authoritative DNS Servers. Top Level DNS Server knows which Authoritative server is maintaining the IPs for the .GOV websites or the .Info websites.
Authoritative DNS Servers
Authoritative Servers keep the record of actual websites and they return the IP address of the website. The query is returned back to the same root. First, the IP Address goes to Top level DNS Server. Next, it does to Root DNS Server then it does to ISP DNS Server.
At this point, ISP DNS Server keeps a record for future queries for the same website and returns the IP Address to the router’s public IP address. The router provides the IP to the browser and then the browser.
The browser creates another query but this time it has an IP Address, not the domain name. The query goes directly to the server of the website and the server returns the homepage of the website.
I hope you have understood the concept of DNS and how a website opens on your computer screen. Feel free to comment if you have any confusion.
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