ESRI FileGDB (File GeoDatabase) must be in a zip file. You will be prompted what you want feature classes you wish to load.
We do not support Raster Geodatabases. Any vector feature classes are supported. Viewing geometry and attributes. This is the most common format for ESRI ArcMap and ArcGIS Pro. Also if you have a Layer Package (LPK) you can unzip that with 7zip and it includes a FileGeoDatabase. We do not support LYR files with symbology, labeling, scale dependencies.