Name server Facts for Kids

A name server is like a special phone book for computers on the internet. Imagine you want to visit a website like "example.com". Your computer doesn't know where "example.com" lives directly. Instead, it asks a name server. The name server then translates that easy-to-remember name ("example.com") into a secret number code called an IP address (like 192.0.2.1). This IP address is what computers actually use to find each other.

The most common type of name server is part of the Domain Name System (DNS). DNS servers are super important because they help your computer find websites, send emails, and connect to other online services by turning human-friendly names into computer-friendly numbers.

How Domain Name Servers Work
Types of Name Servers
See also

How Domain Name Servers Work

The internet uses two main ways to identify things:

Domain names: These are the easy-to-remember names like "google.com" or "wikipedia.org".
IP addresses: These are the number codes like "172.217.160.142" that computers use.

The Domain Name System (DNS) connects these two. Think of it as a giant, worldwide directory. When you type a website name into your browser, your computer asks a DNS server for the IP address.

There are special "root name servers" at the very top of the DNS system. They are managed by an organization called ICANN. These root servers know where to send your computer to find the next level of DNS servers, and so on, until it finds the right IP address. DNS servers are located all over the world, working together to keep the internet running smoothly.

A DNS name server stores special information called DNS records. These records include:

Address (A, AAAA) records: These link a domain name to an IP address.
Name server (NS) records: These tell you which name servers are in charge of a specific domain.
Mail exchanger (MX) records: These tell computers where to send emails for a domain.

Types of Name Servers

Name servers usually work in one of two ways: they are either authoritative or recursive. Sometimes, a name server can do both jobs!

Authoritative Name Server

An authoritative name server is like the official record keeper for a specific part of the internet, called a "zone." If you ask an authoritative server about a name in its zone, it will give you the official answer. It only gives answers for the names it is responsible for.

There are two kinds of authoritative servers:

Primary server: This is the main server that holds the original, most up-to-date information for a zone.
Secondary server: This server makes an exact copy of the primary server's information. It updates itself automatically to make sure it always has the same data as the primary. This helps if the primary server goes down; the secondary can take over.

Every domain name on the internet has one or more authoritative name servers. When you register a domain name (like "yourwebsite.com"), you tell the domain registrar which name servers are authoritative for your domain. These servers are then listed in the internet's main directories, so other computers know where to find the official information for your website.

Authoritative Answer

When an authoritative name server gives an answer, it marks that answer as "authoritative." This means it's the official, direct answer from the server that manages that specific domain name. If a server gives an answer it got from somewhere else (like a cached answer), it won't mark it as authoritative.

Recursive Resolver

A recursive resolver (sometimes called a recursive name server) is like a helpful librarian. When your computer asks it a question (a "recursive query") about a website, this server goes out and finds the answer for you. It doesn't necessarily have the answer itself.

Here's how it works: 1. Your computer asks the recursive resolver for the IP address of "example.com". 2. If the resolver doesn't know, it starts asking other name servers, starting from the root servers. 3. It keeps asking different servers, moving down the DNS hierarchy, until it finds the authoritative server that knows the answer for "example.com". 4. Once it gets the answer, it sends it back to your computer.

Recursive resolvers are very useful because your computer doesn't have to do all the searching itself. Most internet service providers (ISPs) give their customers access to recursive resolvers.

Caching Name Server

Caching name servers are usually recursive resolvers that save the answers they find for a certain amount of time. This is like remembering a phone number after you've looked it up once.

Why is this helpful?

Faster answers: If someone else asks for the same website, the caching server already has the answer and can give it much faster.
Less internet traffic: It reduces the number of times servers have to ask each other for information, making the internet more efficient.
Less work for authoritative servers: It takes some of the load off the main authoritative servers.

Many home internet routers also have a small caching name server built in to help your home network run faster.

Name server facts for kids

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