Pretty much. A lot depends on how things are configured and set-up.
AFAIK in general it’s something like
HTTP Request for a folder.
eg. http://mysite/somefolder/
If there is an index.php file serve that
If there is no index.php file, but there is an index.html file serve that
If there is neither an index.php nor an index.html file show a list of the folders content.
IMHO Options -Indexes is a lot easier than putting “nothing to see here” files in folders, but it is commonly done.