The point of origin of an earthquake is called the focus, while the spot on the Earth's surface directly above this center is called the epicenter.

Here's a breakdown:

* Focus: This is the point *within* the Earth where the earthquake originates. It's the actual location where the rupture occurs along a fault. Think of it as the "starting point" of the earthquake.

* Epicenter: This is the point on the Earth's surface directly above the focus. It's the point where the earthquake's seismic waves reach the surface first. The epicenter is where we usually experience the strongest shaking from an earthquake.

Here's an analogy to help visualize it:

Imagine you have a balloon. If you poke a hole in the balloon, the point where you poked the hole is like the focus. The spot on the outside of the balloon directly above the hole is like the epicenter.