For the Moon or an artificial satellite moving around the Earth in an elliptical orbit, the distance between the object and the Earth changes throughout the orbit. The point of maximum separation from the Earth is known as the apogee (from the Greek apo = away from). At this point in the orbit, the object is moving at its slowest speed (Kepler’s Second Law). The apogee refers specifically to orbits around the Earth, and is equivalent to the apoapsis of a general orbit. The point of closest approach between the Earth and a celestial object orbiting it is the perigee.
The Moon moves around the Earth in an elliptical orbit (the orbit has been exaggerated in this diagram). The Moon is at apogee when it has its maximum separation from the Earth.

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