A professor is someone who is really good at something and gets paid to teach others about it. Think of them like a teacher who is really focused on one subject, like math or history.
When people go to college, they take classes with professors to learn more about a specific subject. Professors are like experts who have spent lots of time studying and researching a topic, so they know a lot about it.
Being a professor is a very important job because the things they teach can be really complicated and hard to understand. They use special words and concepts that regular people might not know, but professors are really good at explaining it in a way that makes sense.
So, in short, a professor is a smart person who teaches people about a subject they are really good at!