The full form of .ORG is Organization

The domain name org is a generic top-level domain (gTLD) of the Domain Name System (DNS) used on the Internet. The name is truncated from organization. It was one of the original domains established in 1985, and has been operated by the Public Interest Registry since 2003. The domain was originally “intended as the miscellaneous TLD for organizations that didn’t fit anywhere else.” It is commonly used by non-profit organizations, open-source projects, and communities, but is an open domain that can be used by anyone. The number of registered domains in org has increased from fewer than one million in the 1990s, to ten million in 2012, and held steady between ten and eleven million since then.

An organization, or organisation, is an entity – such as a company, an institution, or an association – comprising one or more people and having a particular purpose. The word is derived from the Greek word organon, which means tool or instrument, musical instrument, and organ.