What Is DNS Server in Simple Words?
A DNS server is an essential component of the internet infrastructure that helps us navigate the vast network of websites and services available online. DNS stands for Domain Name System, and it acts as a directory that translates human-readable domain names, such as www.example.com, into machine-readable IP addresses, like 192.168.0.1.
How Does a DNS Server Work?
When you enter a website address into your web browser’s address bar, your computer sends a request to a DNS server to obtain the corresponding IP address. The DNS server then looks up its database, which contains a list of domain names and their corresponding IP addresses.
- The first step is for your computer to send a query to the recursive DNS resolver, which is typically provided by your Internet Service Provider (ISP).
- If the resolver has the requested information in its cache memory, it returns the IP address immediately.
- If not, the recursive resolver contacts other DNS servers to find the answer.
The hierarchy of DNS servers ensures efficient and reliable resolution of domain names. At the top of this hierarchy are the root servers that store information about top-level domains (TLDs) like .com, .org, and .net.
To optimize performance and reduce network traffic, DNS resolvers implement caching mechanisms. When a resolver receives an answer from a DNS server, it stores it in its cache memory for future use. This caching reduces response times for subsequent requests to the same domain name.
However, these caches have an expiration time known as Time-to-Live (TTL). Once this time elapses or if there are updates made to a domain’s IP address, the resolver needs to fetch the latest information from the authoritative DNS server.
Authoritative DNS Servers
Authoritative DNS servers are responsible for storing and providing the accurate IP addresses associated with specific domain names. When an authoritative server receives a request for a domain it manages, it responds with the corresponding IP address.
Domain owners or administrators typically manage authoritative DNS servers. These servers contain information about their own domains and can delegate subdomains to other authoritative servers if necessary.
In simple terms, a DNS server acts as an interpreter between human-readable domain names and machine-readable IP addresses. It helps our devices find and connect to websites by providing accurate and up-to-date information about domain name resolution.
Understanding how DNS servers work is crucial for troubleshooting network issues, optimizing website performance, and ensuring reliable access to online resources.