What is DNS (Domain Name System)?

What is DNS (Domain Name System)?

DNS is the system that provides the connection between domain names and IP addresses of internet sites. In short, DNS converts domain names to IP addresses so you can access any website you want without entering complex IP addresses into your internet browser.

For example, to enter Google, one of the most visited websites in the world, you need to enter an IP address of 172.217.23.14. However, thanks to the DNS system, typing www.google.com into your internet browser will be sufficient. DNS servers connect the written domain name and IP address and open the Google website.

How Does DNS Work?

The DNS system works through servers located in many different parts of the world, called DNS servers. This system establishes a connection between the domain name and the IP address within seconds, without you realizing it. The DNS system basically consists of 4 sub-servers.

1. DNS Cursor

This sub-server is the first server you encounter in the DNS system. When you type a domain name in your internet browser, the domain name is greeted by the DNS cursor and subjected to a deep query. If the query is successful, further steps are taken.

2. Root Server

The domain name passing through the DNS cursor comes to the root server and begins to be resolved there. At this point, simple domain names, which we can see visually, reveal the complex IP addresses they carry. There are different types of DNS resolvers.

3.TLD Server

The TLD server, like the root server, is part of the parsing process. In this final resolution step, the domain name is converted to the IP address it represents. Every website is resolved by the .com TLD server at the end of the domain name.

4. Authorized Server

The place where everything happens is the authoritative server. The domain name was queried in the DNS cursor and resolved in the root and TLD servers reach the authorized server like the IP address. If the proxy server accesses the record of the IP address, the website opens. If there is no access, additional information is requested by the cursor.

DNS Resolvers

There are different types of DNS resolvers as we explained in the root server step. These; It is a recursive DNS resolver and authoritative DNS resolver. These two resolvers, which look similar, actually have quite different roles in the DNS system.

1. Recursive DNS Resolver

The recursive DNS resolver is the responsive resolver that can be repeatedly requested by the client. What this server does is to search the cache for the answers to the question marks in the resolution process until the domain name reaches the authorized server and reveals the necessary records.

2. Authorized DNS Resolver

The authoritative DNS resolver works with the authoritative server and is responsible for keeping all records. It is the last link in the long parsing chain. At the end of the process that resolves the domain name and reaches the IP address it represents, the authorized server opens the website without the need for another query thanks to the authorized DNS resolver.

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