Okay, so let's think of it like we're playing a game!
Imagine we have a bunch of friends who all have different ways they like to play a game. Some like to play very fast, others like to take their time and plan things out, and some like to do a mix of both.
These ways of playing are called temperaments. And just like our friends, different parts of our body (like our brain and our stomach) also have different ways they like to do things.
So, if we want to win our game, we need to make sure all of our friends' ways of playing are working together and not just doing their own thing. That's called a functional ensemble.
Now, when it comes to our body, a functional ensemble of temperament means that different parts of our body are working together in harmony to help us stay healthy and happy. So, if we take care of each part of our body and make sure they're all working together, we'll be healthier and happier overall!