Living organisms have certain life processes in common. There are seven things that they need to do to count as being alive. The phrase MRS GREN is one way to remember them:
It can be easy to tell if something is living or not. A teddy bear might look like a bear, but it cannot do any of the seven things it needs to be able to do to count as being alive.
A car can move, it gets energy from petrol (like nutrition and respiration), it might have a car alarm (sensitivity), and it gets rid of waste gases through its exhaust pipe (excretion). But it cannot grow or make baby cars. So a car is not alive.