Users of ArcGIS regularly use file geodatabases when attribute tables exceed the storage capacity of a shapefile attribute table (an individual DBF file is limited to ~2GB in size).
The file geodatabase format has emerged as a very common format for storing and exchanging spatial data, particularly considering that it allows for the storage of multiple data layers, and that it allows for the storage of data layers that exceed the limits of other specifications. Despite the widely held misconception that file geodatabases (.gdb) can only be read and edited using tools within Esri's ArcGIS platform, recent versions of GDAL (and, therefore, GDAL-utilizing applications like QGIS) are capable of efficiently reading and extracting information from file geodatabases.
