Okay kiddo, let me explain what a rewrite rule is in a very simple way.
You know when you read a book and you have to flip through the pages to find the chapter you want to read? A rewrite rule is like a shortcut that helps you find the chapter you want to read faster.
In websites, a rewrite rule is a type of command that helps the website find the right webpage when you type in the web address. It's like a shortcut that tells your computer where to go if you type in a certain web address.
For example, if you type in www.google.com, the rewrite rule will tell your computer to go to the Google search page. Without the rewrite rule, your computer wouldn't know where to go and you wouldn't be able to access the Google search page.
So, a rewrite rule is kind of like a map that helps your computer find the right webpage quickly and easily. Pretty cool, huh?