First of all, the professional answer:
Angel investment is when an individual investor (angel investor) uses their own funds to make an early-stage investment in a start-up or small business. These investors are typically seasoned entrepreneurs or high-net-worth individuals who not only provide financial support to the business, but may also provide resources such as management experience, business networks, and access to markets. Angel investment mostly occurs in the seed or start-up stage of enterprise development, when the company often does not have a mature business model or stable cash flow, so the risk is higher, but the potential return is also larger. Angel investment plays an important role in promoting technological innovation and entrepreneurial activities, it is the front-end link of venture capital, and is often seen as an important way for high-tech start-ups to obtain funding.
Let's continue to explain it in layman's terms:
Imagine that your friend has a great idea and wants to start a company, but doesn't have enough money to make that dream come true. At this time, you believe that your friend's idea is promising and decide to use your own money to help him start the business. Not only did you give him start-up capital, but you also used your experience and connections to help him run the company better and avoid some common mistakes. This investment you make is angel investment. Angel investors are like "angels" who fall from the sky to help companies take off at the beginning stage. However, because it is the initial stage of the company, it is very risky, and it is possible that the money you invest will be wasted, but if you see it right and the company succeeds, your return on investment may be very considerable.