Subset

Okay kiddo, imagine I have a big bag of different colored candies. Some are red, some are blue, some are green, and so on.

Now let's say I take out all the red candies from the bag and put them on one side. That group of red candies is called a subset. It's a smaller group of candies that are just a part of the big group.

So, a subset is just a smaller group of things that are selected from a bigger group. It's like having a group of toys, and then picking out only the cars to make a subset of just cars.