Okay kiddo, so there's something called "rational basis review" that helps decide if a law or policy is fair and okay to have. Basically, it's like a game where the government has to explain why they made the law, and if their reason makes sense or is "rational", then the law is okay to have.
For example, let's say there's a law that says you have to wear a helmet while riding a bike. The government would say they made this law to protect people's heads from getting hurt if they fall off their bikes. And that reason makes sense, so the law is okay to have.
But if the government made a law that said only people with green eyes can ride bikes, then that reason doesn't make any sense! It's not "rational" because eye color doesn't have anything to do with biking. So that law wouldn't be okay to have.
Overall, rational basis review is like a way to make sure the government has a good reason for making laws and policies.