Funds brought into a business by its shareholders is called equity. It is a measure of a stake of a person or group of persons starting a business.
What does investing in equity mean?
When you buy a company's equity, you are in effect financing it, and being compensated with a stake in the business. You become part-owner of the company, entitled to dividends and other benefits that the company may announce, but without any guarantee of a return on your investments.