Say it like this

The person with the problem. Without one of these, there is no business, only a hobby.

For the grown-up

A customer is the person whose problem the business exists to solve and who decides, by paying or not paying, whether it was worth solving. That decision is the only honest verdict available on whether a thing is useful.

The easy mistake

Careful here. Children often assume the business decides what is good. The customer decides. That reversal is most of what separates a business from a project.

Words next to this one

Business Somebody fixing a problem for somebody else, who says thank you with money. Price How much money somebody is asking for a thing. Not the same as what it is worth to you. Value How much something is worth to you. It can be different for two people looking at the same thing. Entrepreneur Someone who notices a problem and decides to be the one who fixes it.