Here's the breakdown:

* Newton's Third Law: This law states that for every action, there is an equal and opposite reaction.

* Rocket Propulsion: A rocket engine burns fuel, creating hot, expanding gases. These gases are expelled out of the nozzle at high velocity.

* Action & Reaction: The action is the rocket engine pushing the exhaust gases downwards. The reaction is the exhaust gases pushing back on the rocket, propelling it upwards.

Think of it this way:

Imagine you're standing on a skateboard and throw a heavy ball forward. You'll feel yourself pushed backward. The same principle applies to a rocket. The force of the exhaust pushing down is what makes the rocket go up!