Buffer analysis is one form of basic spatial analysis. It takes the vector representation (point, line, or polygon) of a real-world feature, and then creates a buffer zone based on a defined distance from the feature’s border. Thus, the created buffer zone is an area whose boundary always has the same distance to the input vector feature, e.g. the buffer zone for a point feature is a circle. Real-world examples for buffer zones could be protected areas along rivers or around nature conservation areas, or represent a simple proximity analysis. In the latter case, the buffer analysis is usually the first step of the analysis, followed by an overlay of the buffer zone with the target features to find those target features within the buffer zone, and thus within a certain distance of the original feature. Usually, the buffer zone extends outwards from the feature, but polygons can also have inner buffer zones. If the buffer zones from multiple features overlap, the analyst can decide to leave the individual boundaries of the buffer zones intact, or to dissolve them, i.e. merging the overlapping buffer zones into one larger buffer zone. The size of the buffer zone, i.e. the distance of its boundary from the original feature’s boundary, can be based on an uniform numerical value and associated spatial unit, but often, it is based on an attribute value (numerical or class) of the feature. Conceptually, buffering using raster representations of real-world features is similar a proximity analysis with a regular grid of square polygons: Departing from raster cells that form the area to be buffered, all raster cells that fall within the designated distance (overlay) from the buffer zone. With buffer analysis being a basic analytical operation, practically every GIS and many other analysis tools provide this functionality.