Buffer
Creates a new geometry expanded (or shrunk) by a distance around the input geometry.
Category: Operations
Definition (expanded)
Buffer grows or contracts shapes by a distance in the geometry’s CRS units (degrees in EPSG:4326, meters in many projected CRSs). Buffering in lon/lat degrees is often misleading unless the tool uses geodesic buffering. For accurate meter-based buffers, reproject to a suitable projected CRS first.
Related terms
SimplifyReduces vertex count while approximating the shape to improve performance and reduce file size.ProjectionA mathematical method for mapping the curved Earth to a flat plane, which affects distance, area, and shape.GeodesicMeasurements or operations computed on the curved Earth model rather than a flat plane.ToleranceA threshold distance used by simplify, snapping, and some repair operations.Reprojection (coordinate transformation)Converting coordinates from one CRS to another (e.g., EPSG:4326 lon/lat → EPSG:3857 meters).