# How DNS Resolution Works Across the Internet, every website you open uses names like [google.com](http://google.com), [facebook.com](http://facebook.com), or [amazon.com](http://amazon.com). But computers do not understand names. They only understand IP addresses. To convert names into IP addresses, we use a system called DNS. In this blog we will understand what is DNS and why name resolution exists, what is the dig command, how DNS resolution happens step by step using **root, TLD,** and **authoritative name servers**, and how this connects to real browser requests. First, let’s understand what is DNS and why name resolution exists. ## **What is DNS and why name resolution exists** DNS (Domain Name System) is like the phonebook of the Internet(typical definition). Humans like to remember names such as [google.com](http://google.com), but computers need numbers such as 14.1.2.4. DNS exists to convert domain names into IP addresses. When you type a website name in the browser, DNS finds the correct IP address of that website so your computer can connect to the correct server. Without DNS, we would need to remember IP addresses for every website, which is not practical. ## **What is the dig command and when it is used** dig (Domain Information Groper) is a command-line tool used to query DNS servers and inspect how name resolution works. It is mainly used by developers, system administrators, and network engineers to debug DNS problems, check name servers, and understand how DNS resolution is happening. Using dig, we can see: * Which name servers are involved * Which records are returned * How the DNS query travels step by step Now let’s understand how DNS resolution happens in layers. ### **Understanding dig . NS and root name servers** ```bash dig . ns ``` This command asks: Who are the name servers for the root of the DNS system? The dot (.) represents the root zone. Root name servers are the top-level servers in the DNS hierarchy. They do not know IP addresses of websites. They only know where to find TLD (Top-Level Domain) servers such as .com, .org, .in Root servers are the starting point of every DNS lookup. ### **Understanding dig com NS and TLD name servers** ```bash dig com NS ``` This command asks: Who manages the .com domain? The response gives the list of TLD name servers responsible for all .com websites. These servers do not know the IP address of [google.com](http://google.com) yet. They only know where the authoritative servers for [google.com](http://google.com) are located. So now we move one layer deeper. **Understanding dig** [**google.com**](http://google.com) **NS and authoritative name servers** ```bash dig google.com NS ``` This command asks: Which name servers are responsible for [google.com](http://google.com)? The result gives the authoritative name servers for [google.com](http://google.com). These servers are the final authority for [google.com](http://google.com). They store the actual DNS records such as: * IP addresses * Mail servers * Other DNS information Now we are very close to the final answer. ### **Understanding dig** [**google.com**](http://google.com) **and the full DNS resolution flow** ![](https://cdn.hashnode.com/res/hashnode/image/upload/v1769094624754/3a43d2a1-6cce-4212-91b3-6a054b8a96d9.png align="center") ```bash dig google.com ``` This command asks directly for the IP address of [google.com](http://google.com). Behind the scenes, the resolver follows this path: 1. First, it contacts a root server. Root server replies with TLD servers for .com. 2. Then it contacts a .com TLD server. TLD server replies with authoritative servers for [google.com](http://google.com). 3. Then it contacts an authoritative server for [google.com](http://google.com). Authoritative server replies with the final IP address. Finally, the resolver returns the IP address to your computer. Now your browser can connect to the correct web server and load the website. **What NS records represent and why they matter** NS (Name Server) records tell which servers are responsible for a domain. They are very important because: * They define who controls the domain * They guide the resolver to the correct authoritative servers * Without correct NS records, websites will not resolve Want to know more about NS records read this blog : [**What DNS records are and why they exist**](https://blog.suprabhat.site/what-dns-records-are-and-why-they-exist) ### **How recursive resolvers use this information** Your computer does not directly talk to root servers. It sends the query to a recursive resolver (usually provided by your ISP or Google DNS). The recursive resolver: * Starts from root servers * Goes to TLD servers * Goes to authoritative servers * Caches the result for future use This makes DNS faster and efficient for repeated requests. **Connecting dig** [**google.com**](http://google.com) **to real browser requests** When you type [google.com](http://google.com) in your browser, the same DNS process happens. **Browser → Recursive Resolver Resolver → Root → TLD → Authoritative Authoritative → IP Address returned Browser → Connects to server using TCP Website loads** So every web request depends on DNS before any data transfer starts. ## **Conclusion** DNS is the hidden system that makes the Internet usable by converting names into IP addresses. The dig command helps us see how DNS resolution works step by step, from root servers to authoritative servers. Understanding this flow gives a clear picture of how browsers find the correct servers and how the Internet routes requests correctly every time you open a website.