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 address, 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 even hosted by a separate service provider. Using a subdomain can be quite practical if you'd like to have different sites that are connected in some way. As an example, you can have an on-line store under the main domain along with a forum under a subdomain so as to supply means for your customers to ask questions and share opinions about your products. The best thing about employing a subdomain rather than a subfolder is that the websites will be separated, so you are able to update one of them or perform maintenance without affecting the other.