ELI5: Explain Like I'm 5

Cokernel

Alright kiddo, imagine you have blocks of different colors and you want to put them in order. You start by putting all the blocks of the same color together in a line. You now have several lines of different colors. But what if you want to simplify it and group these lines that are the same?

This is where a cokernel comes in. It helps to group these lines together, making them easier to understand. In math, a cokernel is used when you have two functions that are related but you want to simplify them.

Let's say you have two functions: f(x) = 2x and g(x) = 3x. These functions are related because g(x) can be expressed as f(x) multiplied by a constant 1.5. If you graph these functions, they would be parallel lines.

Now, we want to simplify these functions and make them into one function. This is where the cokernel comes in. The cokernel takes the related functions, in this case f(x) and g(x), and groups them together by removing the overlap between them.

The cokernel of these functions would be the line y = 0 because it represents the difference between the two functions. When we group the functions together using the cokernel, we end up with a simpler, easier to understand function.

So, in summary, a cokernel is a way to simplify related functions by removing the overlap between them and grouping them together. It's like organizing blocks of different colors into simple lines and grouping them together to make it easier to understand.