The force that gives a thrown ball its vertical movement is gravity.

Here's why:

* Gravity is a constant force: It pulls everything towards the center of the Earth.

* Vertical motion: When you throw a ball, you give it an initial upward velocity. But gravity acts on the ball continuously, slowing it down as it goes up.

* Peak and descent: Eventually, gravity brings the ball to a stop momentarily at its highest point. Then, gravity continues to pull it down, causing the ball to accelerate downwards until it reaches the ground.

So, while you might throw the ball horizontally, gravity is the force responsible for its upward and downward motion.