The highest normal orbits for satellites are geostationary (sometimes called geosynchronous); a constant speed lets the satellite maintain the same view of Earth all the time.
LEO stands for Low-Earth Orbit, an area starting just 100 miles up where most communication satellites are beginning to go. It’s close enough to transmit e-mail, voice, or other data to portable phones, television dishes, computers and other communication devices. A satellite at this height takes about an hour and a half to go around the Earth.
There are other satellites orbiting at various places in between. Spacecraft need to reach a speed of about 17,500 miles an hour to get into orbit.