Orbiting hundreds or thousands of miles overhead are weather satellites which provide continuous coverage of weather conditions around the planet. These satellites are grouped into two main categories: geostationary satellites, and polar orbiting satellites. More detailed information on weather satellites is available at http://noaasis.noaa.gov/NOAASIS/ml/genlsatl.html
Geostationary Satellites orbit at a precise height above the planet (22,300 miles) where they make exactly one orbit around the planet every day. Since the earth turns exactly one rotation every day, the satellite appears to hang motionless above a single spot on the ground. This means each image is taken from the same spot above the earth -- making it easy to create animations or "loops" of the cloud motion over time. NOAA operates two geostationary satellites:
GOES-12 (east) and GOES-10 (west).
Polar Orbiting satellites orbit much closer to the earth and can take much clearer pictures below. However, they are constantly moving relative to the ground and only pass over a particular area twice per day. Because of their much higher resolution, polar orbiting satellites are often used for research. Meteorologists forecasting for arctic regions also use polar orbiters since geostationary satellites can not view far northern and southern areas well. NOAA operates five polar orbiting satellites: NOAA-11, 12, 14, 15, and 16.
weather.gov 
