What is a  Business Angel – a Wikipedia-Definition
Business Angel
An angel investor (also known as a business angel, informal investor, angel funder, private investor, or seed investor) is an affluent individual who provides capital for a business start-up, usually in exchange for convertible debt or ownership equity. A small but increasing number of angel investors invest online through equity crowdfunding or organize themselves into angel groups or angel networks to share research and pool their investment capital, as well as to provide advice to their portfolio companies.

Typical  investments of Business Angels range between 10.000 € and 1 Mio €.