A subdomain is a website url, that is under a main, or a root domain name. One example is something.domain.com, where 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 even hosted by a separate service provider. Employing a subdomain can be quite handy if you wish to have different sites that are connected in some way. As an example, you may have an online store under the main domain as well as a forum under a subdomain so as to provide means for your clients to ask questions or share opinions concerning your products. The best thing about employing a subdomain as opposed to a subfolder is that the web sites are going to be separated, so you're able to update one of them or perform maintenance not affecting the other.