A subdomain is a website url, that is under a main, or a root domain. An illustration is something.domain.com, where domain.com is the main domain address, while "something" is the subdomain below it. Each subdomain can have its own site and records i.e. aside from using the domain name as a part of the whole web address, a subdomain can be entirely independent and also hosted by a different provider. Employing a subdomain can be extremely practical if you'd like to have different sites that are connected in some way. For instance, you can have an online store under the main domain along with a forum under a subdomain in order to supply means for your clients to ask questions and share experiences concerning your products. The best thing about 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 not affecting the other.