Add link to Wikipedia article on WMS

grid_models.md

@@ -52,9 +52,10 @@ $ gdal_translate -ot Int16 -of GTiff -b 1 NETCDF:"tmp/result.nc":WARNING_STATUS
 ```
 *This selects the first timestep (`-b 1`) of result.nc, specifically the WARNING_STATUS variable, and creates a GeoTIFF file from this.*
 
-### Set up a WMS Service
+### Set up a WMS (Web Map Service)
+[Introduction to WMS (Wikipedia)](https://en.wikipedia.org/wiki/Web_Map_Service)
 
-## The structure of the WMS Service
+## The structure of the WMS
 VIPS expects the WMS Service to follow certain patterns in order to display it in a map.
 
 ### Model metadata