system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: When you become partner at a corporation, why must you "buy-in" and what happens with your money?
gpt
You cannot become a partner at a corporation; you can become a partner at a partnership (sometimes called a "firm") or you can become a shareholder of a corporation.

In both cases, the money you contribute becomes the property of the company, and can be used however the managers of the company wish to use it. Since you are now one of the owners of the company, you will receive a fair share of all future profits, and have a vote in how the company is managed and by whom.