Suggest an editImprove this articleRefine the answer for “What is DNS?”. Your changes go to moderation before they’re published.Approval requiredContentWhat you’re changing🇺🇸EN🇺🇦UAPreviewTitle (EN)Short answer (EN)**DNS (Domain Name System)** is an application-layer service and protocol that translates human-readable domain names into IP addresses. In short, it is the "phone book of the internet". **Key point:** DNS only reports the IP address of the server you need - it does not load websites or transfer pages.Shown above the full answer for quick recall.Answer (EN)Image**DNS (Domain Name System)** is an **application-layer service and protocol** that **translates human-readable domain names into IP addresses**. In short: **DNS is the "phone book of the internet"**. --- ## Why DNS is needed Computers on a network **do not understand website names**, they only work with IP addresses (for example: `142.250.184.206`). But it is inconvenient for people to remember those, so we use names instead: - `google.com` - `wikipedia.org` - `example.com` **DNS links a site's name to its IP address**. --- ## How DNS works (simplified) When you enter a site's address in a browser: 1. The browser asks: "What is the IP address of `example.com`?" 2. The DNS server looks up the match 3. The DNS server replies: "The IP address is such-and-such" 4. The browser then **connects to the server by IP** Without DNS, the internet as we know it **would not work**. --- ## An important point for interviews DNS **does not load websites** and **does not transfer pages**. It **only reports the IP address** of where to go next. --- ## DNS hierarchy (briefly) DNS is organized as a hierarchy: - root DNS servers - top-level domain servers (`.com`, `.org`) - servers for specific domains This lets DNS: - be distributed - work fast - have no single point of failure --- ## What data DNS stores DNS can store: - a site's IP address - mail server addresses - service information about a domain The most important and most commonly asked about: **domain → IP address** --- ## A real-life example DNS is like the contacts on your phone: - you look up a person's name - the phone shows the number - then you call that number --- ## Short answer for the interview A ready-made phrasing: > **DNS is an application-layer system and protocol designed to translate domain names into IP addresses, so a client can find the right server on the network.**For the reviewerNote to the moderator (optional)Visible only to the moderator. Helps review go faster.