A subdomain is a website address, that's under a main, or a root domain name. One example is something.domain.com, where domain.com is the main domain, while "something" is the subdomain below it. Each subdomain can have its own site and records i.e. aside from employing the domain name as a part of the whole web address, a subdomain can be completely independent and also hosted by a different provider. Using a subdomain can be quite practical if you'd like to have different web sites that are related in some way. For example, you may have an online store under the main domain as well as a forum under a subdomain in order to offer means for your customers to ask questions and share thoughts concerning your products. The best thing about employing a subdomain rather than a subfolder is that the websites are going to be separated, so you're able to update one of them or perform maintenance without affecting the other.