An organization (or organisation — see spelling differences) is a social arrangement which pursues collective goals, which controls its own performance, and which has a boundary separating it from its environment. The word itself is derived from the Greek word ὄργανον (organon [itself derived from the better-known word ἔργον ergon - work; deed - > ergonomics, etc]) meaning tool. The term is used in both daily and scientific English in multiple ways.

In the social sciences, organizations are studied by researchers from several disciplines, the most common of which are sociology, economics, political science, psychology, management, and organizational communication. The broad area is commonly referred to as organizational studies, organizational behavior or organization analysis. Therefore, a number of different theories and perspectives exist, some of which are compatible, and others that are competing.

• Organization – process-related: an entity is being (re-)organized (organization as task or action).
• Organization – functional: organization as a function of how entities like businesses or state authorities are used (organization as a permanent structure).
• Organization – institutional: an entity is an organization (organization as an actual purposeful structure within a social context)