What Is DNS?

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What Is DNS?

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Short Definition
DNS, or Domain Name System, is a hierarchical naming system that identifies computers on the Internet and/or other Internet Protocol networks.
Extended Definition

The Domain Name System can be described as the phone book of the Internet that translates domain names, such as hth.guide, to IP addresses. In other words, the records in the DNS system associate domain names with other forms of information. This so-called phone book manages the mapping between names that humans can read, and numbers that are read by machines. DNS servers convert name requests into IP addresses, and administer the communication between a server and an end user. These requests are also known as DNS queries.

All devices connected to the internet have their unique IP addresses, and these addresses are used by other machines to find a specific device. In short, DNS servers remove the need for humans to memorize IP addresses. Whenever an end user wants to reach a specific page, a translation happens between what the user types into the web browser, and the address needed to locate that required page. In other words, DNS resolution means converting a hostname (hth.guide) into a computer-friendly IP address.

Four DNS servers are required for a web page to load:

  • DNS recursor – the server designed to receive queries from client machines through applications such as web browsers.
  • Root nameserver – the server that translates human readable host names into IP addresses.
  • TLD nameserver – the server that enables the next needed step in the search for a specific IP address, hosting the last part of a hostname. For example, in hth.guide, the TLD server is “guide”.
  • Authoritative nameserver – the server that returns the IP address for the requested hostname back to the DNS recursor.

One of the most crucial purposes and functionalities of the DNS is its fundamental role in distributed services, such as cloud providers and content delivery networks.

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