Access Control on the manager directory/folder

Hi, I’m curious if I add Access Control over the manager folder to add additional authentication on the manager for the site... My question is, is there any part of the frontend that needs files that are part of the backend/manager that is going to pop up the authentication box that a user is going to need to view the site.

Sometimes I feel like I’m speaking french when I talk about computers. Hopefully everyone understands what I’m asking.