system
Given the following post, respond as if you're commenting on Reddit:
human
Eli5: What's the difference between a CEO, President, Owner, Principal, Chair, and all the other "top boss person" titles?

I assume some of it has to do with types of corporations, public/private, etc. But I know nothing.
gpt
CEO is the guy running the company. He doesn't necessarily own even a small part of the company, he just does the work of, well, executing all the company's actions.

President is pretty vague, it's loosely the "leader" of the company and, when the office is held by someone who is not the CEO, the CEO is usually still the one calling the shots. President's do not have to be a part owner either, it is simply a salaried position.

Owner is the person (or one of the people) who actually owns the organization. They may have a substantial stake in the organization or only own a small part of it. 

Principal is just a substantial investor in the company. Usually, though not necessarily, they'll be helping to run the company as well.