Packages 
Package Description
org.gdal.gdal
Provides the classes necessary to handle GDAL rasters.
org.gdal.gdalconst
Various constants used by the org.gdal.gdal package.
org.gdal.gnm  
org.gdal.ogr
Provides the classes necessary to handle OGR vector datasources.
org.gdal.osr
Provides the classes necessary to handle spatial reference systems and transformation between them.