What is DNS?

The Domain Name System, or DNS, is a fundamental part of the internet that translates human-friendly domain names into IP addresses that computers use to identify and communicate with each other. As a beginner, understanding DNS can help you grasp how the internet functions behind the scenes, and how websites and online services are accessed. In this article, we’ll break down the basics of DNS and explain its importance in the online world.

Imagine you’re trying to visit a friend’s house, but instead of knowing their street address, you only know their name. To find their house, you need to look up their address in a directory. DNS works in a similar way, serving as a global directory that translates domain names (e.g., www.example.com) into IP addresses (e.g., 192.0.2.1) that computers use to locate and connect to websites or online services.

When you enter a domain name into your web browser or click on a link, your computer needs to find the corresponding IP address to load the website or service. This process, known as DNS resolution, involves a series of queries to DNS servers. Here’s a simplified overview of the steps involved:

1. Your computer sends a DNS query to a recursive resolver, usually provided by your internet service provider (ISP) or a third-party DNS service.
2. The recursive resolver forwards the query to a root server, which provides a referral to the top-level domain (TLD) server responsible for the domain’s TLD (e.g., .com, .org, .net).
3. The TLD server then refers the query to the authoritative name server responsible for the specific domain.
4. The authoritative name server returns the IP address associated with the domain name to the recursive resolver.
5. The recursive resolver sends the IP address back to your computer, which uses it to establish a connection with the web server hosting the website or online service.

DNS plays a crucial role in the performance and reliability of the internet. To ensure fast and accurate DNS resolution, DNS servers rely on caching – temporarily storing IP addresses and domain names for a set period of time. This reduces the need for repeated queries and improves the overall speed of accessing websites and online services.

In summary, DNS is the essential system that connects domain names to IP addresses, enabling users to access websites and online services using easily memorable names rather than numerical IP addresses. By providing a global directory and facilitating the resolution process, DNS ensures the seamless functioning of the internet and allows users to navigate the online world with ease.