Genus (mathematics)

A genus in mathematics is like a special name for the shape of a surface, like the outside of a ball or a donut. Think of it like different types of ice cream - vanilla and chocolate are different "flavors" of ice cream just like a ball and a donut are different "genuses" in mathematics.

So, a genus is a way to describe the shape of an object in a special language that mathematicians use. It helps them talk and think about shapes more easily, sort of like how we have different words for different colors (red, blue, green, etc.). By having different words for different shapes, mathematicians can better describe and study them.