domain in DNS

What is Domain in DNS?

A grouping of TCP/IP hosts in the hierarchical Domain Name System (DNS). Domains are the building blocks of DNS. A domain consists of a group of nodes in the DNS namespace. Domains are organized hierarchically in the DNS namespace, with the topmost domain called the root domain.

DNS domains can be classified as one of the following:

• A parent domain, which contains other domains. An example of a parent domain is microsoft.com.
• A child domain, or subdomain, which is contained within a parent domain. Examples of child domains in the microsoft.com parent domain are northwind.microsoft.com and marketing.microsoft.com.