If you would like keep some content hidden from the public eye, you are able to activate password protection for a specific folder - either the main site folder or another one below it. If this feature is enabled, a pop-up will appear every time someone attempts to open the folder in question or clicks on a direct link that goes a few levels deeper, so login info will be necessary for www.domain.com/folder/image.jpg if you have protected just the domain.com folder. If the credentials are not valid, a “403 Forbidden” message will appear and there isn't any way to get around this restriction, so you can be certain that no one shall be able access the protected content. The option can be useful in a variety of cases - if only some individuals should be able to see particular files, if you work on a site and you don't want people to see it before it's completed, and so on.