Okay kiddo, imagine you're walking down the road or on a train track and you come across something called a "cant". A cant is a small angle or slope that is designed to help keep you and the train safe!
Let's think about it like this- if a train were to go around a curve without a cant, it wouldn't be able to stay on the tracks and could possibly tip over! That's why cants were invented. The cant allows the train to lean a little bit towards the inside of the curve, stopping it from falling off the tracks.
This is also applicable to roads! When you're driving on a winding road, you'll notice that the outer edge of the road is a little bit higher than the inside, giving you a gentle slope that helps you stay on the road, especially around curves.
So, a cant is a small slope that helps you and trains stay safe and stop from falling off tracks or roads when going around turns or curves. Pretty neat, huh?