Let’s speak on business angels, who are also known as angel investors or sometimes simply angels. Who are they and what role do they play in the world of business? Usually it is an affluent individual investor who provides some sum of money or capital for a business start-up in exchange for ownership equity. As a rule business angels do not get the majority of stocks, so they do not have the controlling interest. As far as I know they do not usually get more than 25% of stocks but get a blocking minority ownership that allows to veto the decision of the Board of Directors.
I’ve tried to find the origins of this term and I have succeeded. The term "angel" originally comes from well-known Broadway Theatre District in New-York where it was used to describe wealthy individuals who provided money for theatrical productions. In 1978, William Wetzel completed his pioneering study on how entrepreneurs raised seed capital in USA. He was the first one to use the term "angel" in order to describe the investors that supported theatres. Angel investors are often retired businessmen, who may be interested in angel investing for reasons that are far beyond pure income. For example, they may want to keep abreast of current developments in some business arenas. Moreover, in addition to providing the capital, angel investors can offer valuable management advice and important contacts.
Angel investors’ capital fills the gap in start-up financing between "friends and family"—(sometimes humorously given the acronym FFF, which stands for "friends, family and fools") who provide seed funding—and formal venture capital. Although it is usually difficult to raise more than a few hundred thousand dollars from friends and family, most traditional venture capital funds are usually not able to make small investments under 1–2 million dollars. There is no “set amount” for angel investors, and the range can go anywhere from a few thousand, to a few million