What are the directories D & M doing in my cryptomator dekstop test directory

I stumbled acros cryptomator and i love what it does esspecially for cloud storage.
However how simple it is i don´t understand it sorry.
Here is my qń.
I make a test directory and save it in my dropbox directory (desktop)
The test directory than has in dropbox 2 directoryś D & M and 2 fcryptomater files
What are these 2 directoryś doing there ?
I did not made them in the cryptomator app
Please explain
Im using ubunty 18.04 LTS

we’ll, here we go:
I recommend to have a look into the Knowledge Base also for further information

Oh wonderfull i tried it and it worked
Now all i have to do is remembering it :rofl::grinning::rofl:
Thanks a lot