LibreOffice on linux (Ubuntu 19.10 in my case) can be lauched in two different mode from terminal, invisible mode and headless mode:
the manual says:
--invisible Starts in invisible mode. Neither the start-up logo nor the initial program window will be visible. LO can be controlled and documents and dialogs can be opened via the API. When started with this parameter, it can only be quit using the taskmanager (Windows) or the kill command (UNIX based systems). --quickstart does not work with this parameter. --headless Starts in "headless mode", which allows using the application without user a interface. This special mode can be used when the application is controlled by external clients via the API. It implies --invisible and strictly ignores any GUI environment. --quickstart does not work with this parameter.
To my eyes those definition are very similar (almost thei does the same thing). So when I shuld use one instead of other?
Also what does it mean that “strictly ignores any GUI environment”? it’s implies lossing user configuration set up from interface? It use a fresh user to start in headless?