Kernel of a function

Okay kiddo, imagine you have a magic box that can do some cool stuff like turning bananas into apples.

Now imagine you put in some fruits like bananas, apples, and oranges into the box and it only turns bananas into apples and the other fruits stay the same.

The bananas that turned into apples are called the "kernel" of this box. It's the part of the fruits that were affected by the magic box.

In the same way, a kernel of a function is the part of the input that affects the output. Not all inputs will change the output of the function, but only certain ones.

So, just like how the magic box only changes the bananas, the kernel of a function is the part that changes when different inputs are used.