This is a picture demonstrating Newton's third law. It has an action force pushing the skateboard forward and a reaction force pushing back with the same force in the opposite direction.

This picture below shows an engine pushing exaust back and exaust exerting an equal, but opposite force on the engine.

This is a picture from Nasa.com

---Newton’s third law (law of reciprocal actions) states that whenever an object exerts a force on another object the other object exerts the same force back in the opposite direction. The two forces basically act on the same line. The two forces are equal in magnitude
and opposite in direction. For every action there is always an equal reaction. The reaction force is equal, but it is also in the opposite direction.
---There are many examples of Newton’s third law. When we walk on we exert a force on the earth’s surface that is equal to our weight. The earth’s surface exerts a reaction on the body in an upward direction with the same force that was exerted on it. The reaction
equals the same amount of force as the weight that pushed down on the earth’s surface. Another example would be if two identical golf carts started directly in front of each other and tried to accelerate with the same force they wouldn’t move at all. This would be a great example of an equal, but opposite force. These were a few examples of Newton’s third law.