Name Server Basics

A Name Server is a crucial component of the DNS (Domain Name System). It acts as the actual database that stores and responds to requests for IP address information (DNS records) associated with domain names. Without Name Servers, the internet could only function using raw IP addresses instead of domain names.

1. Primary Roles of Name Servers

The functionality of Name Servers is generally categorized into two main types:

① Authoritative Name Server

This server officially manages and stores the final DNS records for a specific domain (e.g., google.com).

Role: Set up by the domain owner, it holds the accurate IP address (A record), mail server address (MX record), etc., and provides the final answer to DNS queries.
Characteristic: The information stored here is the Source of Truth for that domain.

② Recursive Name Server / Resolver

This server acts as an intermediary on behalf of the client (user) to process queries.

Role: Since it doesn't hold the final answer, it sequentially queries the Root Server, TLD Server, and finally the Authoritative Name Server, and then returns the discovered IP address to the user.
Characteristic: To provide fast and efficient service, it caches query results for a specific time.

2. Types of Name Servers (Hierarchical)

DNS has a hierarchical structure, and different types of Name Servers exist at each level:

Root Name Server: At the top of the DNS hierarchy. It knows the addresses of the TLD servers.
TLD Name Server (Top-Level Domain): Manages top-level domains like .com, .net, and .kr. It knows the address of the Authoritative Name Server for domains under its TLD (e.g., example.com).
Authoritative Name Server: The final server that holds and responds with the specific IP address for a particular domain.

3. Name Servers and Domain Registration