Landuse and land cover assessment is very important subject in earth sciences studies, the availability of data and computer resources are necessary to perform image processing and remote sensing manipulation. With the newweb based software for remote sensing developed by Google (Google earth engine), users around the world can work easily and without high cost and time efforts. This software does not need a high computer performance neither graphical or calculator processor unit; many applications can be realized using the GEE platform. This chapter aim to introduce some basic functions used to process data of remote sensing for some applications in earth sciences. Normalized difference vegetation index NDVI, Normalized difference salinity index NDSI are calculated from Sentinel and Modis dataset for the North of Algeria.