The beefy server part is for taking the gigantic OSM world database and turning it into vector data that can be consumed by the client. I believe Osmand runs th

The beefy server part is for taking the gigantic OSM world database and turning it into vector data that can be consumed by the client. I believe Osmand runs their own beefy servers to pregenerate vector data for download, though it’s also possible to use Osmand Map Creator to generate your own vector data on your desktop.