Itô's theorem is like a fancy tool that some really smart people use to understand how things change over time. Imagine you have a toy car that you can move around on a track, and you want to figure out how the speed of the car changes over time. Itô's theorem is like a tool that helps you do this.
The first thing you need to know is that the car's speed doesn't just change randomly. It depends on lots of things, like how hard you're pushing the car and whether it's going uphill or downhill. All of these things are like little pieces of information that we call "variables".
Itô's theorem helps us figure out how all of these variables work together to change the car's speed. It does this by breaking down the changes in speed into really tiny steps, like a little step-by-step instruction manual. Each tiny step tells us how one variable affects the car's speed in just a tiny, tiny way. And then we put all of these tiny steps together to get the big picture of how the car's speed changes over time.
So basically, Itô's theorem is like a magic tool that helps us understand how things change over time, by breaking down big changes into lots of tiny steps that are easier to understand. It helps super smart people do lots of really cool math stuff to understand how things work in the world around us.