More specifically, how can I theoretically find the files that is in a website's root directory?
For example:
My current imaginary website has 2 folders (labeled rescources and screenies) and 3 files (labeled index.html, index.alt.html, and favicon.ico).
I am aware that, if no index.html or index.php exists, Apache automatically routes users that attempts to visit that virtual host to a directory page giving raw access to the files in the root folder (or whichever folder they specify).
Because most folders and or root directories of people's web servers have an index.html or index.php, the average user cannot access a directory page listing all files in the active directory... Right?
Is there a way that, not including brute-forcing to attempt to find the directory name, a user can find my rescources or screenies folders, or even my index.alt.html without being told to navigate to https://[MY_SERVER]/rescources/ or has found where an html file that they have access to has referenced it?