Suggest an editImprove this articleRefine the answer for “What is a DNS server?”. Your changes go to moderation before they’re published.Approval requiredContentWhat you’re changing🇺🇸EN🇺🇦UAPreviewTitle (EN)Short answer (EN)**A DNS server** is a **server that answers DNS queries and reports which IP address corresponds to a domain name**. **Key point:** a DNS server does not transmit sites or data, it only reports the address, and the client connects to it on its own.Shown above the full answer for quick recall.Answer (EN)Image**A DNS server** is a **server that answers DNS queries and reports which IP address corresponds to a domain name**. In simpler terms: **a DNS server tells the computer exactly where on the internet it needs to connect**. --- ## Why a DNS server is needed When you type in the browser: ``` example.com ``` the computer **does not know** where this site is located. It asks the DNS server: > "What is the IP address of [example.com](http://example.com)?" **The DNS server looks for the answer and returns the IP**. Without DNS servers: - sites would not open by name - applications and services could not work --- ## What a DNS server does The main tasks of a DNS server: - accepts DNS queries - looks up the "domain -> IP" mapping - returns the answer to the client - may cache answers to speed things up A DNS server **does not transmit sites or data**, it only reports the address. --- ## How a DNS server works (simplified) 1. The client sends a DNS query 2. The DNS server: - either finds the answer itself - or asks other DNS servers 3. The DNS server returns the IP address 4. The client connects to the needed server by IP --- ## Types of DNS servers (briefly) For understanding in an interview, it is important to know that DNS servers come in different kinds: ### Recursive DNS server - accepts the request from the client - "walks" through other DNS servers itself - returns the final answer Usually this is: - the provider's DNS - public DNS (Google, Cloudflare) --- ### Authoritative DNS server - **knows the exact data about the domain** - stores the domain's DNS records - does not ask other servers --- ## Important points for an interview - a DNS server is **not a single server**, but part of a distributed system - DNS servers work **around the clock and automatically** - if DNS servers fail, sites become **unreachable by name** - a DNS server operates at the **application layer of OSI** --- ## Real-life example A DNS server is like a directory assistance service: - you give a name - you are told a number - then you call it yourself --- ## Short interview answer Remember this formulation: > **A DNS server is a server that processes DNS queries and returns the IP address that corresponds to a domain name, allowing the client to find the right server on the network.**For the reviewerNote to the moderator (optional)Visible only to the moderator. Helps review go faster.