A satellite on a polar orbit is passing over polar regions of a planet during each rotation. There are many polar orbits and they are located between 100 and 1000 km over the Earth’s surface. A full rotation by a satellite on a polar orbit is usually short – 1-3 hours.
Many Earth-observing satellites are placed on polar orbits (e.g. the Landsat series) as well as the International Space Station Alpha.
Visualisation of Landsat satellite travelling on a polar orbit.