Subdomain

A domain name with a prefix name; for example, the domain name for Computer Hope is "www.computerhope.com", if we wanted to have a FQDN for a sub page or another external domain such as our help section, we would create "help.computerhope.com" as a subdomain.

Subdomains are often used for links to frequently accessed portions of the site, which allows users to only need to remember the domain and not a long URL.