My question is about the basic structure of a .gpkg file. When I make a .gpkg file, they only ever contain one layer, and I cannot add additional layers to them. However, sometimes when I have added and then exported the vector layers as .qgz files and the completed map as .qgt files, all left in the same directory as the .qpkg file, they will show up in the layers or associations of the .gpkg file, IF I have saved the .gpkg file after performing all these operations.
As an example, following the above to create these files and saving them all in the same directory, would show two layers when I opened the .gpkg file: X.gpkg - contains polygons [layer 1] Y.gqz - contains points [layer 2] Y.gqt - contains themes for map made [not seen as layer, but accessible via SHOW LAYOUT MANAGER]
Is there a way that I could save all this so that it was just in one .gpkg file? Or instead is the .gpkg file always found with its corresponding layer files as separate files?
I've watched numerous videos on YouTube, read the documentation but am still fundamentally confused about this.