Geoprocessing is commonly used at the data preparation stage, before a spatial analysis. It includes clipping by project area for data preparation, buffering for environmental impact analysis, generating grids and random points for data sampling, generating Voronoi polygons from voting sites for accessibility analysis, rasterising a vector layer output for additional spatial analysis using a raster calculator, and so on. In the section, we will explain common geoprocessing activities for GIS projects.