What is DNS

DNS (Domain Name System) is one of the fundamental infrastructures of the Internet. This article introduces the basic concepts and working principles of DNS.

In essence, DNS service is like a Xinhua Dictionary; by consulting the dictionary, we can find the IP address corresponding to a domain name.

DNS Introduction

DNS (Domain Name System) is one of the fundamental infrastructures of the Internet. Like a Xinhua Dictionary, it is responsible for translating human-readable domain names into IP addresses that computers can understand.

DNS Resolution Principle

How DNS Works

When you enter a URL in your browser:

  1. The browser first checks the local cache.
  2. If not found, it initiates a query to a DNS server.
  3. The DNS server returns the corresponding IP address.
  4. The browser uses that IP address to access the target website.

Key Concepts

  • Domain Name: A human-readable address for a website, e.g., www.nullprivate.com
  • URL (Uniform Resource Locator): The complete web address, including protocol, domain name, and path, e.g., https://www.nullprivate.com
  • IP Address: A numerical identifier for network devices, e.g., 1.1.1.1
  • DNS Server: A computer that provides domain name resolution services
  • Web Hosting: Storing website files on a server so they can be accessed over the Internet