Okay, so imagine you are playing with your toys and your friends. You guys all have different toys, right? Some of you have dolls, some of you have cars, and some have building blocks.
Now, imagine if one day, the grown-ups came and said, "Okay, from now on, only the kids who have cars can play together. The kids with dolls and building blocks have to play separately."
That's like what caste is. It's a fancy grown-up word for saying that people are put into groups based on where they were born or what their family is like. In some places, it's like saying that only the kids with cars can play together and the kids with dolls and building blocks can't.
In caste politics, grown-ups use these groups to try to get more power or money. They might promise things like jobs or protection to the people in their same caste, and not care so much about the people in other castes. It's kind of like when one kid tries to be the leader and only lets the other kids with cars play the games they want to play.
But just like how playing with all kinds of toys is more fun than only playing with one kind, having friends from all different castes can make life better for everyone. It's important for grown-ups to remember that everyone should have the chance to play together, no matter what kinds of toys they have.