Newton's third law states that to every action, there is an equal and opposite reaction.
If that's the case, then how do things move at all? Shouldn't all applied forces be canceled by the equal and opposite force it experiences from the object they were applied to?
Newton's third law doesn't imply that things can't move but it does imply conservation of momentum and energy.
Imagine a scenario where an astronaut is in orbit so they don't feel the affects of gravity. If there is an object floating and they push on it (apply a force to it) we know intuitively that the object will start to accelerate in the direction of the force.
Newton's third law tells us that the astronaut will also start moving in the opposite direction of the force they are applying.
In turn, as the object and astronaut move they push air molecules which push more and so on. If you follow this reasoning through you'll see that ultimately applying a force conserves the total momentum and energy of a system but does not prevent movement of objects within the system.
You must have to think about the mass of the object. Same force will be applied on two different objects of different mass. Velocity (movement) will depend on the mass. Whose mass is more it will be at greater velocity than other higher mass object.
Let's say, i jump on the earth. Same Force is applied both on earth and me. Since my mass is very less compared to the earth, i will move (got velocity). And the same force is two small for the earth two move.
Another example a train stroked a flee. A trained applied a very little force to the flee since the mass of the flee is so small.
