Money lent to a corporation that promises to pay the loan back with interest is known as

 corporate bonds 

A corporate bond is a bond issued by a corporation in order to raise financing for a variety of reasons such as to ongoing operations, M&A, or to expand business.The term is usually applied to longer-term debt instruments, with maturity of at least one year. Corporate debt instruments with maturity shorter than one year are referred to as commercial paper 
Stocks are a type of ownership, which means if the corporation does well the holder does well, and if the corporation deas poorly they could lose all - no interest is paid but profits. .