Question

what criteria do we use to decide whether something is alive,,?

Answer 1

Any visible movement such as walking, breathing, or growing is generally used to decide whether something is alive or not. However, a living organism can also have movements, which are not visible to the naked eye. Therefore, the presence of life processes is a fundamental criterion that can be used to decide whether something is alive or not.

Answer 2

When a body is alive, the clear signs are voluntary actions like movement or locomotion or even blinking, and other signs might be the involuntary actions like breathing, beating of the heart etc.