Free theory

Okay kiddo, let me explain to you what a free theory is. You know how in school we learn about different subjects like math, science, social studies, etc.? These are all called theories or ideas that help us understand the world around us.

A free theory is a bit like that, but it specifically talks about something called "fields". Now, think of fields like a big room with lots of toys in it. Each kind of toy is like a different particle, like a ball or a toy car.

A free theory describes how these particles move around in the room and interact with each other. It's called a "free" theory because the particles don't bump into anything or have any resistance in the room.

So, a free theory is just a way of understanding how particles move around and play with each other in a big room full of toys, without running into anything or being slowed down. Pretty cool, huh?