Satellites are placed in one of three basic orbits:
An elliptical orbit is shaped like a
squished circle (just like the Earth's orbit). A satellite in this
orbit is sometimes closer to Earth than at other times. The point
where a satellite's orbit is closest to Earth is called perigee.
Where the orbit is farthest away is called apogee.
A circular orbit takes a satellite around
the Earth without ever changing its distance from the planet.
Whether an orbit is circular or elliptical, if it passes over the
North and South Poles, it is called a polar orbit.