Respiration (physiology)

Imagine that your body is like a car and it needs fuel to move. That fuel is called oxygen, and you get it by breathing in air. Just like you put gasoline in the car's engine to make it run, you breathe in oxygen to make your body work properly.

Inside your body, the oxygen that you breathe combines with the food that you eat, which creates a lot of energy for your body to use. But just like when the car's engine runs, there's a dirty byproduct that gets created - in your body, that's called carbon dioxide.

If you don't get rid of the carbon dioxide that you create, it can build up and cause problems. So just like the exhaust pipe on a car, you need to get rid of the carbon dioxide that your body produces. That's where breathing out comes in - when you exhale, you're actually getting rid of the carbon dioxide that your body produced.

So respiration is basically the process of breathing in oxygen to give your body energy, and breathing out carbon dioxide to get rid of the waste. It's like putting fuel in the car to make it go, and then clearing out the exhaust so it doesn't get backed up.