A subdomain is a web address, that's under a main, or a root domain. An illustration is something.domain.com, in which domain.com is the main domain name, while "something" is the subdomain below it. Every single subdomain can have its own website and records i.e. apart from employing the domain name as a part of the whole web address, a subdomain can be entirely independent and also hosted by a different company. Employing a subdomain can be extremely handy if you want to have different web sites that are related in some way. For example, you may have a web-based 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 advantage of employing a subdomain rather than a subfolder is that the websites will be separated, so you're able to update one of them or perform maintenance without affecting the other.