Okay kiddo, a company is like a big group of people who work together to do something. Just like how you and your friends work together to build a tower with your blocks, a company is a lot of adults who work together to make stuff or sell stuff.
Sometimes a company makes things like toys or clothes, and sometimes they sell things like food in a restaurant or services like fixing cars. The company makes money by selling what they make or do, and then they can use that money to pay their workers and to make more things.
Companies can be really big, with lots and lots of people working together, or they can be small, with just a few people. But they all have one thing in common: they are groups of people who are working together to achieve something.