Thanks for your answer! I have finally just understood the difference between SFTP (SSH FTP) and FTPS (FTP over SSL) ... Before I got into detail with this stuff, I thought, the "S" in front is simply indicating a secure FTP connection, and that would be SSL.
Btw. FileZilla can switch to exlicit or implicit FTP over TLS (which apparently is SSL(?)) and SFTP, too.
Sorry for this noob-question from an IT guy :roll: