It's a type of integration with local file handling:
- you see every folder and file in explorer / finder.
- they are just filenames but without the data
- they act normal and can be copy pasted renamed etc
- the moment a file is opened the first time, the data gets synced locally.
I use it to connect to rather large folders (bigger then my SSD) because it only takes up space of the files in use.
Is "choosing which files and folders" an upfront configuration thing, or does it happen "on the fly" when opening a file?