What is the difference between a satellite and a sensor?

A satellite is a manmade object sent into orbit around the Earth. A sensor is a sophisticated, camera-like device that can detect and record information about the Earth. A sensor can be mounted onto an aircraft or onto a satellite. While the aircraft is flying or the satellite is orbiting, the sensor is pointed toward the Earth to collect data about the areas below. Remote sensing scientists download and analyze the data, which can be processed with computers into pictures of the Earth. These pictures acquired from sensors onboard aircraft or satellites are called "remotely sensed imagery."