A subdomain is a website address, that is under a main, or a root domain. An example is something.domain.com, in which domain.com is the main domain address, while "something" is the subdomain below it. Every single subdomain can have its own website and records i.e. apart from using the domain name as a part of the whole web address, a subdomain can be completely independent and even hosted by a separate service provider. Employing a subdomain can be very handy if you'd like to have different web sites which are associated in some way. As an example, you may have an on-line store under the main domain as well as a forum under a subdomain so as to supply means for your customers to ask questions and / or share views concerning your products. The benefit of employing a subdomain instead of a subfolder is that the web sites will be separated, so that you can update one of them or perform maintenance not affecting the other.