How DNS Was Invented and Why We Need Domain Names
In the previous post, we learned that every device connected to the internet has an IP address. An IP address acts like the address of a house, allowing data to reach the correct destination.
However, this created a new problem.
Computers can easily work with numbers, but humans are much better at remembering words than long strings of numbers.
For example, which is easier to remember?
142.250.190.78 or google.com
Most people would choose the second one.
As the internet grew, remembering the IP address of every computer and website became almost impossible. A better solution was needed.
The Early Days Before DNS
In the early years of the internet, there was no Domain Name System (DNS).
Instead, every computer connected to the network stored a special text file called the HOSTS.TXT file.
This file contained a list of computer names along with their corresponding IP addresses.
Whenever a computer wanted to connect to another computer, it looked through this file to find the correct IP address.
At first, this system worked well because only a small number of computers were connected to the internet.
As more universities, research laboratories, government organizations, and businesses joined the network, the HOSTS file kept growing larger.
Every computer had to regularly download an updated version of this file to ensure it had the latest information.
Eventually, the file became too large to manage efficiently.
Problems with the HOSTS File
The HOSTS file had several major problems.
First, it had to be updated frequently as new computers joined the network.
Second, every computer needed to download the latest version manually or through scheduled updates.
Third, if the file was outdated, users might connect to the wrong computer or fail to connect at all.
As the internet continued growing, it became clear that this system could not support millions of computers.
Researchers needed a better and more scalable solution.
The Birth of DNS
In 1983, computer scientist Paul Mockapetris designed the Domain Name System, commonly known as DNS.
Instead of storing every computer name in one giant file, DNS introduced a distributed system.
Rather than relying on a single list, many DNS servers around the world would work together to store and provide domain name information.
This made the system much faster, easier to maintain, and capable of growing with the internet.
How DNS Works
Suppose you type example.com into your web browser.
Your computer does not automatically know where that website is located.
It first sends a request to a DNS server asking:
"What is the IP address for example.com?"
The DNS server looks up the answer and returns the corresponding IP address.
Your browser then uses that IP address to connect to the correct web server.
All of this usually happens in a fraction of a second.
You only see the domain name, while DNS performs the translation behind the scenes.
An Everyday Example
Think of DNS as the contacts app on your smartphone.
You save a person's name, such as "John," instead of memorizing their phone number.
When you tap John's name, your phone automatically uses the correct phone number to make the call.
Similarly, you type a domain name such as example.com, and DNS automatically finds the correct IP address needed to connect to the website.
What Is a Domain Name?
A domain name is the human-readable name of a website.
Some examples include:
google.com
wikipedia.org
github.com
Instead of remembering the numerical IP address of each website, users only need to remember its domain name.
This makes the internet much easier to use.
Understanding the Parts of a Domain Name
A domain name is made up of different parts.
Consider the following example:
blog.example.com
The last part, ".com", is called the Top-Level Domain (TLD).
The middle part, "example", is the Second-Level Domain, which is usually the name chosen by the website owner.
The first part, "blog", is called a subdomain. Organizations often use subdomains to separate different sections of their websites, such as blog.example.com or mail.example.com.
Why DNS Is Important
Without DNS, every internet user would have to remember the IP address of every website they wanted to visit.
Imagine trying to remember the numerical addresses for hundreds of websites that you use every month.
DNS eliminates this problem by translating easy-to-remember domain names into IP addresses automatically.
It is one of the most important services on the internet and operates continuously in the background every time you visit a website, send an email, or use many online applications.
DNS Today
Although the internet has grown from a few connected computers to billions of devices worldwide, the basic purpose of DNS remains the same.
Modern DNS systems are distributed across thousands of servers around the world, making them fast, reliable, and capable of handling billions of DNS requests every day.
Whenever you type a website address into your browser, DNS quietly performs its job within milliseconds, allowing you to reach the correct destination without ever needing to know its IP address.
Without DNS, using the internet would be far more difficult, and the simple act of visiting a website would require remembering long numerical addresses instead of easy-to-read names.