Q: I have 2 questions:

1. what is the incongruity between common stocks and preferred stocks?

2. If you were to start a business of your own, would you organize it as a sole proprietorship, a partnership,

A: 1. Preferred stocks get primacy if the company is liquidated. For other differences -- do a search online!
2. The construct of a business would depend on what the business is doing. While the first three can apply to almost anything, something that's a non-profit