Intersection theory

Imagine you have a toy town with roads going in all directions. You also have some toy cars that are driving around town. Now, let's say that each time two roads meet, we call it an intersection.

Intersection theory is the study of what happens when we look at these intersections in a more complicated setting. Instead of just looking at roads and cars, we might look at more abstract objects like shapes or spaces.

For example, imagine we are looking at a big square shape. Inside this shape, we draw a smaller triangle shape. Where the corners of the triangle meet the sides of the square, we have intersections. In intersection theory, we look at how these intersections behave in relation to each other and how they interact with the shapes involved.

Sometimes these intersections are simple and easy to count, but sometimes they become more complicated and require special tools to understand. One important concept in intersection theory is the idea of degrees. Imagine you have a ruler and you can measure the size of an intersection. This measurement is known as the degree of the intersection.

Overall, intersection theory helps us better understand how different shapes and spaces intersect with each other, and can be a powerful tool in understanding how things such as surfaces or shapes intersect with each other in a bigger picture.