The epicenter, epicentre (/ˈɛpɪsɛntər/) or epicentrum in seismology is the point on the Earth's surface directly above a hypocenter or focus, the point where an earthquake or an underground explosion originates.
They use them to be more specific instead of using general words. For example: At my school, Summit Academy, we have great teachers. Summit Academy, between the two commas, was the appositive.
