Alright kiddo, let me explain what a power law is.
Imagine you have a bunch of toys, let's say balls, and you want to arrange them by size from the smallest to the largest. When you do that, you might notice that most of the balls are small, and only a few are really big. This is similar to a power law, where a few things have a really big impact, while most things have a small impact.
This idea can be seen in lots of things, like how many people have a lot of money, while most people have less money. Or, how only a few websites get lots of visitors, while most websites get very few.
A power law is just a way to describe this pattern, where a few things or events have a big impact, while most things or events have a small impact. Hope that helps you understand, kiddo!