WMS 1.3.0 defines three operations of GetCapabilities, GetMap and GetFeatureInfo, in which the GetFeatureInfo operation is an optional operation. WMS standardizes implementation and use of WMS operations in HTTP (Hypertext Transfer Protocol) distributed computing platform (DCP).

• GetCapabilities, returns service-level metadata.
• GetMap, returns a map image whose geospatial and dimensional parameters are well-defined.
• GetFeatureInfo, returns information about particular features shown on a map.