Question

what living is as opposed to the non-living?

Answer 1

An isolated metabolic reaction(s) outside the body of an organism, performed in a test tube is neither living nor non-living. Hence, while metabolism is a defining feature of all living organisms without exception, isolated metabolic reactions in vitro are not living things but surelyliving reactions.

Answer 2

In simple terms, a living being, or an organism performs all the important biological functions of life and responds to stimuli.

Anything which doesn't do so is non living.