Answer:
Planets move in orbits around the Sun. Sometimes they are closer, sometimes
farther away. The point where a planet is closest to the Sun in its orbit is called
perihelion; the farthest point from the Sun in the orbit is called aphelion.
Satellites move in orbits around their planets. Sometimes they are closer, sometimes
farther away. The point where our moon is closest to the Earth in its orbit is called
perigee; the farthest point from the Earth in the moon's orbit is called apogee.