Subdomain

=Subdomain= A subdomain, also known as a canonical or a third-level domain, is a domain within a domain. For example, if the domain name was google.com, then mail.google.com would be a subdomain of google.com. ccTLD should not be confused with a subdomain.

The hierarchy of the Domain Name System/DNS is -

Top-Level Domain/TLD ( .com) Second-level domain (google.com) Subdomain (mail.google.com) Host name (www. )

Online shops (such as ebay) and information sites (about.com) often use subdomains to organize information. Sites such as Wikipedia use subdomains to add different language options (en.wikipedia.org; zh.wikipedia.org). Subdomains can also be used in busy sites in which they identify different computers with the same information, and when someone types in the URL of that website a system called load balancing takes the site visitor to one of multiple computers. Under a domain, any number of subdomains can be created free of charge.

Author: Sarah Zhou