GeoServer is an open source map server written in Java that allows users to share and edit geospatial data. It is one of the popular open source map servers that can publish OGC compliant services such as WMS and WFS. Web Map Service (WMS) is used for publishing georeferenced images and simple querying. On the other side, Web Feature Service (WFS) is used for publishing vector data to any kind of GIS clients. WFS is mostly used for data sharing purposes.
In this recipe, we will use one of GeoServer's standard published service named
topp:states in WMS format. As stated in the Adding WMS layers to maps recipe of this chapter, WMS has different request types such as