Overlay (map overlay)
An extra layer drawn on top of a basemap, such as tiles, GeoJSON, or a raster like GeoTIFF.
Category: Mapping
Definition (expanded)
Overlays help you compare your geometry to other data. Common overlays include XYZ tiles, WMS layers, GeoJSON boundaries, and GeoTIFF rasters. Performance depends on file size, tiling, and how much is rendered at once.
Related terms
XYZ tilesA web mapping tiling scheme where map images are requested as /{z}/{x}/{y}.png (or similar).WMS (Web Map Service)An OGC standard for serving map images over HTTP, often used as raster overlays.WMTS (Web Map Tile Service)An OGC standard for serving cached map tiles, similar to XYZ tiles but with a defined tile matrix.GeoJSONA JSON format for geographic features, using objects like Feature, FeatureCollection, and geometry types like Polygon and MultiPolygon.GeoTIFFA TIFF raster image format that can include georeferencing, commonly used for satellite and aerial data.COG (Cloud Optimized GeoTIFF)A GeoTIFF organized for HTTP range requests so clients can stream only the parts they need.