Living things have several key characteristics:
1) They can move and change positions. They breathe through lungs, stomata, or other respiratory structures and need oxygen.
2) They need to consume and metabolize energy sources, either through photosynthesis as autotrophs or by consuming other organisms as heterotrophs.
3) They grow in size and complexity through development and can respond to external and internal stimuli in their environment.
4) All living things have the ability to reproduce and pass their genetic material to offspring. They also excrete metabolic waste.