Social business, as the term had once been commonly used, was first defined by Nobel Peace Prize laureate Prof. Muhammad Yunus and is described in his books Creating a world without poverty—Social Business and the future of capitalism and Building Social Business—The new kind of capitalism that serves humanity's most pressing needs.
In these books, Yunus defined a Social Business a business:
Unlike a profit-maximizing business, the prime aim of a Social Business is not to maximize profits (although generating profits is desired). Furthermore, business owners are not receiving any dividend out of the business profits, if any.
On the other hand, unlike a non-profit, a Social Business is not dependent on donations or on private or public grants to survive and to operate, because, as any other business, it is self-sustainable. Furthermore, unlike a non-profit, where funds are spent only once on the field, funds in a Social Business are invested to increase and improve the business' operations on the field on an indefinite basis. Per Yunus' quote: "A charity dollar has only one life; a Social Business dollar can be invested over and over again."