I used to see lots of /etc/<something>.conf
files used to configure the system, making it clear via the <something>
what is to be configured (I would call this "config files").
This trusted and imho working system seems however not to be sufficient, as more and more I encounter what I would name "config directories" which I often perceive to be structrured like:
/etc/<something>.conf/
|-<file1>
|-<file2>
|-<file3>
creating a situation where the settings in the single files (<file1>, <file2>, <file3>
) where all the containing files are (in my perception) merelye concantenated before being used like the "config file" before.
Since it cannot be merely that people felt the urge to reinvent the wheel, just so it was "invented here", there must be a reason for resorting to "config directories".
I wonder hence, what is the use-case of "config directories", that made them necessary in the first place?
Are there some core essential things, that modivate to use a config directory over a plain config file?
Example