Try to imagine that you need to call someone knowing only their name, but not their phone number. You open the contacts on your smartphone, find the name, and the device automatically dials the correct number. DNS performs a very similar, invisible yet absolutely essential task every time you go online.

It is one of the fundamental technologies that works in the background 24/7. Without it, the modern internet as we know it simply could not function. You would have to remember not website addresses, but complex numeric combinations. DNS saves us from this by acting as a universal and fast translator.

What DNS Is and Why It’s Needed

Simply put, DNS is the internet’s address book. Computers cannot work with domain names like example.com. They need numerical IP addresses to locate servers and exchange data.

The purpose of DNS is to translate human-readable domain names into machine-readable IP addresses. Thanks to DNS, we can type familiar website names without memorizing long strings of numbers.

It’s important to understand that DNS is not used only for accessing websites. Many other internet services depend on it working correctly:

• email delivery (mail servers find each other via domain names);

• cloud storage services and online applications;

• video conferencing systems and messengers;

• access to APIs of various web services.

How a DNS Query Is Processed

When you enter a website address, a multi-step process begins. In most cases, it takes less than a second.

Checking the Local Cache

First, the system checks its “short-term memory.” The browser, the operating system, and even your router store the results of recent DNS queries. If you’ve visited the site recently, the IP address may be found immediately, significantly speeding up page loading.

Contacting a Recursive Resolver

If the required record is not found in the local cache, the request is sent to a recursive DNS resolver. This role is usually performed by your internet provider’s server, although public alternatives can also be configured.

Searching the DNS Hierarchy

The resolver acts like a persistent courier that doesn’t stop until it finds an answer. If the information is not in its large cache, it starts traversing the system:

• first, it contacts the root servers, which direct it to the appropriate domain zone (for example, .ru);

• then it queries the top-level domain (TLD) servers, which point to the authoritative servers for the specific domain;

• finally, the authoritative domain servers return the exact IP address.

Completing the Request and Caching

The obtained IP address is sent back to your device, after which the browser can establish a direct connection to the web server. The result is cached at all levels — from the local device to the resolver — speeding up future requests to the same website.

Why DNS Matters for Users

DNS makes the internet convenient and reliable. Without it:

• you would have to remember the IP addresses of all websites;

• email and many other services would not work correctly;

• websites would become less accessible and slower.

For website and business owners, DNS provides additional flexibility: you can change servers or hosting providers without changing the domain name users see.

In addition, DNS makes it possible to manage domains and subdomains, route traffic to different servers, and scale projects without changing website addresses.

How DNS Speeds Up the Internet

DNS not only translates domain names into IP addresses, but also affects how quickly websites open. To avoid querying remote servers every time, devices and browsers store recently obtained results — this is called DNS caching.

For example, if you visited example.com yesterday, your computer may use the cached IP address today without requesting it again from an external server. As a result, the page loads faster.

However, cache entries have an expiration time. Once it expires, the request goes through the DNS system again, ensuring the data stays up to date. This is especially important when a website owner changes servers or hosting — the old IP address no longer works, and the cache must be refreshed.

What a DNS Query Looks Like Step by Step

Let’s look at a practical example of how DNS works:

1. A user opens example.com.

2. The browser checks the local cache. If the IP address is found, the request goes directly to the server.

3. If the IP is not found, the request is sent to the provider’s DNS server.

4. The provider’s server checks its records. If it doesn’t find them, it forwards the request to the root servers.

5. The root server directs the request to the appropriate domain zone server, such as .com.

6. The zone server forwards the request to the authoritative server for the domain, where the current IP address is stored.

7. The response travels back through the same chain to the user, and the browser connects to the website.

DNS and Scalable Projects

Large internet services use DNS to distribute load. A single domain can point to different servers in different regions. For example, a website may route users from Europe to one server and users from America to another. This reduces load, speeds up page delivery, and makes the site more stable.

This approach is known as geographic traffic distribution. For users, it is completely transparent — they enter the same domain name, and the internet automatically decides which server will handle the request.

Conclusion

DNS is an invisible but critically important component of the internet. It turns familiar domain names into technical IP addresses, ensuring access to websites, email, and online services.

Understanding how DNS works helps website and service owners manage their domains more consciously, resolve technical issues faster, and provide users with reliable access to online resources.