WHAT IS A TRICK AND WHAT IS NOT?

I have some questions and would appreciate your thoughtful input.

What is the difference between teaching a horse a trick and teaching it a movement? Is there a difference?

What’s the difference between teaching a horse to lie down versus teaching a horse to perform flying changes? A horse can do both and does do both in nature. So why do many people consider one to be a trick and the other to be a legitimate training movement?

Why do most of us judge the training of movements in the category of tricks as being less worthy or less valuable to our horses than movements incorporated in other disciplines?