How to link a visitor to a directory of files to download?

As the title suggests, I’m trying to figure out how to create a link, which will take my visitors to a directory-style page containing all the files within that directory…

For Example:
In my server’s main directory, I have a Downloads folder.
This folder contains multiple categories.
I want to be able to list these categories as Links on my page, so that when the visitor clicks it, they can easily navigate through the files that each folder contains, and download the files as-needed.

Can anybody provide me with some advice on how to achieve this?
I would greatly appreciate it!

Thanks in advance!