I have learnt in my second grade that all things are categorised into living and non-living things. Living things breathe , grow, reproduce, etc., I don't really remember... and non-living things don't. I was thinking if there was something that isn't living or non-living; something entirely diiferent. I know about viruses: the threshold between living and non-living. Just asking, but what about stars? It is sort of like a living system, isn't it? It can't be 'completly non-living'. I know my question is vague but I would like to know your opinions.