Introduction into domain info, elements and concepts

In this guide, we will discuss some of the fundamental concepts of a domain information system that will help you figure out your DNS setup.

Domain Name System

The domain name system, better known as "DNS", is a network system that allows us to translate human-friendly names (usually alphabetic) into unique addresses.

A DNS server is a computer designed to translate domain names into IP addresses. These servers do the bulk of the work in the domain name system. Since the total number of domain transfers is too large for any server, each server can redirect a request to other DNS servers or delegate responsibility for the subset of subdomains that are under their responsibility.

Node

Within the domain, its owner can define its own nodes that refer to individual computers or services available through the domain. For example, most domain owners make their web server accessible through the root domain (example.com), as well as through a "site" defined as "www" (www.example.com).

You may have other node definitions under a common domain. You can have API access via the “api” node (api.example.com) or FTP access by designating the node “FTP” or “files” (ftp.example.com or files.example.com). Host names can be arbitrary, provided that they are unique to a given domain.

As mentioned above, DNS is essentially a hierarchical system. At the top of this system is what we call the root DNS server. These servers are under the control of various organizations acting in agreement with ICANN.

Currently 13 root servers are in operation. However, since every minute an unthinkable number of names appear for conversion, each of these servers has a mirror. Interestingly, all mirrors for the same root server share the same IP address. When a request is made to a specific server, it will be redirected to the nearest mirror of this root server.

What do these root servers do? They process requests for top-level domain information. Therefore, if a request arrives for something that the DNS server cannot resolve, the request is redirected to the root DNS server.