* Force: A push or pull that can cause a change in motion. It has both magnitude and direction.

* Acceleration: The rate of change of velocity. It has both magnitude and direction.

* Weight: The force of gravity acting on an object. It has both magnitude and direction (downwards).

* Mass: A fundamental property of matter that represents its resistance to changes in motion (inertia). It only has magnitude.

In summary: Mass is a scalar quantity, meaning it only has magnitude (amount). The other terms are vector quantities, meaning they have both magnitude and direction.