"org" is one of the generic top-level domain name s that can be used when choosing a domain name. It generally describes the entity owning the domain name as one that does not fit into other categories. In general, non-profit organizations and industry standard groups tend to use this generic name. Along with the second-level domain name (for example: "moma" in moma.org), the top-level domain name is required in Web and e-mail addresses.
For more information, see gTLD (generic top-level domain name).