A subdomain is a web address, which is under a main, or a root domain name. One example is something.domain.com, in which domain.com is the main domain address, while "something" is the subdomain below it. Each and every subdomain can have its own website and records i.e. aside from using the domain name as a part of the whole web address, a subdomain can be fully independent and also hosted by a separate service provider. Using a subdomain can be quite practical if you wish to have different websites which are associated in some way. As an example, you can have a web-based store under the main domain as well as a forum under a subdomain in order to supply means for your clients to ask questions and share opinions concerning your products. The benefit of using a subdomain as opposed to a subfolder is that the web sites will be separated, so that you can update one of them or perform maintenance without affecting the other.