Version 3.6 supports several standard spatial data formats to ensure it works across different software environments:
A classic format consisting of at least four files (.shp, .shx, .dbf, .prj). It is compatible with almost all GIS software.
Now the standard format for GADM. It is a single file that can contain multiple layers and is compatible with QGIS and ArcGIS .
For global analysis, you can download the entire world as a single database on the World Download page . Note that these are very large files. Available Data Formats