So, if I push this small box, then it will slide and accelerate with little force. But this bigger box would take more force for the same acceleration because it has more mass. So, the mass X the acceleration is the force being applied.
I'm getting it!
Newton's third and final law is that every action has an equal opposite reaction.
To explain, if I were to hit the table then the amount of force that I applied to it will come back to me. That's why I'm able to feel hitting the table, because it is putting the same amount of force that I put on it.
Wow! I understand so much about motion! Thanks Newton!