One of the main characteristics of living things is the presence of "cells" - most cells contain organelles, carry out respiration, and are able to manage themselves.
Another is reproduction - all living things are able to reproduce, either by asexual or sexual mechanisms.
Homeostasis - living things are able to regulate their living conditions based on the external environment
Growth - most living things grow over time.
Energy acquisition - ability to acquire energy (through digestion or similar processes) and convert it to a usable form (ATP).
Evolution - the process of natural selection as a means to adapt to a certain environment
