Johnson graph

Imagine you have a lot of toys, and you want to put them in different groups. For example, you might have a group of cars and another group of dolls. A Johnson graph is a special way to show how these groups are related.

In a Johnson graph, each group is represented by a circle, called a "vertex." If two groups have something in common, there is a line connecting their vertices. So, if you had a group of red toys and a group of square toys, and some of the red toys were also square, you would draw a line between the red and square vertices.

Johnson graphs can be used for many different things, like analyzing data or understanding how different parts of a system are connected. But ultimately, they're just a way to show how different groups are related to each other.