Geostationary Orbit (GEO)
These satellites are in orbit above the Earth's equator. They stay above the same location on Earth. They are used for telecommunications, television transmission and for navigation.
Low Earth orbit (LEO)
A satellite has a Low Earth Orbit when it orbits somewhere between 300 and 800 km above the Earth's surface. These satellites only take about 90 minutes to go around the Earth. They are ideal for making observations of the Earth's resources.
A polar orbit is a special LEO in which a satellite travels north-south over the Earth's poles, rather than in the more usual east-west direction. Polar orbits can be used to map the complete Earth once a day. This is needed for weather forecasts.
Global Positioning System (GPS) satellites
This is a fleet of satellites which allows us to know exactly where on Earth we are.