This chapter seeks to provide a quick introduction to satellite remote sensing. It starts with a set of definitions, thereby to explain the differences between Earth observations, remote sensing, and satellite remote sensing. It then goes on to describe how satellite remote sensing works, and what the differences between passive and active sensors are. An introduction to the main sensors currently on board active civilian Earth observation satellites is provided, together with details on their key specifications. The complex nature of satellite data, as well as the tools required to manipulate and analyse them are discussed. The chapter ends with a presentation of the main issues to be aware of when dealing with satellite data, and a look at the coming sensors and datasets that will soon expand opportunities for satellite data to inform environmental management.