An organization or organisation (see spelling differences) is an entity comprising multiple people, such as an institution or an association, that has a collective goal and is linked to an external environment.
The word is derived from the Greek word organon, which means "organ".
There are a variety of legal types of organizations, including corporations, governments, non-governmental organizations, political organizations, international organizations, armed forces, charities, not-for-profit corporations, partnerships, cooperatives, and educational institutions.
A hybrid organization is a body that operates in both the public sector and the private sector simultaneously, fulfilling public duties and developing commercial market activities.
A voluntary association is an organization consisting of volunteers. Such organizations may be able to operate without legal formalities, depending on jurisdiction, including informal clubs.
Organizations may also operate in secret and/or illegally in the case of secret societies, criminal organizations and resistance movements.