This document discusses definitions of non-profit organizations. It examines legal definitions based on an organization's status, as well as operational definitions focused on inputs, outputs, and profit distribution. The most widely accepted definition is the structural-operational definition proposed by Salamon and Anheier, which defines non-profits as organized, non-profit distributing, private, self-governing, and voluntary entities. This comprehensive definition forms the basis for how non-profits are categorized in statistical systems like the UN and India's Central Statistical Organization.