Question

What is the difference between living and existing?

Answer 1

If you are alive then you are thriving and using energy.
If you just exist then you MAY be thriving and you MAY be using energy.

There is a difference

Answer 2

Existing is defined as doing what's necessary to stay alive. Those necessary things are eating, breathing, sleeping, hygiene, etc.

Truly living means to use every moment of your existence for what it is. I and you are now living, we're learning, and we're existing.