Thematic mapping is one of the more common uses of spatial data, and the most used thematic maps are the choropleth maps that we already used in several recipes in this book.
Until now, the examples showed you how to produce a thematic map with fixed values in the attributes. SLD specifications define some functions that let you classify your data using related attributes in a dynamic way.
In this recipe, we will explore how to apply symbology encoding to GeoServer layers.