An overview of the end-to-end Remote Sensing process. Starting with the platform, sensor stypes aand orbits are discussed, along with accuracy requirements both radiometrically and spatially. Next, specific sensor characteristics are discussed, including hardware technologies and their limitations, as well as resolution, and image characteristics such as spatial resolution, radiometric dynamic range and saturation effects, as well as calibration. Next, image characteristics are explained, in particular patial, spectral, radiometric and temporal resolutions, data fusion, and image file formats. Lastly the mission is discussed with user needs being of the utmost importance, followed by the needs of the instrument operators and data providers/archivers.