A Web Map Service (WMS) is a standard protocol for serving georeferenced map images over the Internet that are generated by a map server using data from a GIS database.
WMS specifies a number of different request types, two of which are required by any WMS server:
- GetCapabilities - returns parameters about the WMS and the available layers
- GetMap - with parameters provided, returns a map image
Request types that WMS providers may optionally support include:
- GetFeatureInfo
- DescribeLayer
- GetLegendGraphic