Distinguish between the focus and the epicenter of an earthquake.

Epicenter-The point on the Earth's surface located directly above the focus of an earthquake. 

Focus-The point where the earthquake actually begins

A focus is a point on the surface of the earth where the energy is released and the epicentre is the place which is directly above the focus.

Explanation:

An epicenter is the location on the earth where the earthquakes are felt and is a point of the greatest damages on the earth's surface and is in direct contact with the vertical waves of the earthquake that release by the sudden movement so form the focus. The epicenter has the fault zone and is due to this is spread across the raptures. The focus is also called the hypocentre and during all the earthquakes all the waves are directed towards this central point. The fault ruptures occur along with the focus of the earthquake, the rapture earthquakes have more stringer waves and can extend to about 100 km.

Bwould be my guess |-/ 

Ones bigger then than the other