A cooperative is an entity that is owned and controlled by its members, which operates for their benefit. The cooperative landscape includes (among other types) 
  • producer cooperatives, 
  • consumer cooperatives, 
  • multi-stakeholder cooperatives
  • housing cooperatives, 
  • rural electric cooperatives, and 
  • worker cooperatives
The entire cooperative sector in the United States is represented by the National Cooperative Business Association (http://www.ncba.coop).
The International Cooperative Alliance provides a cooperative definition, list of values, and principles on its website: http://ica.coop.