Protect Files is a system security and privacy tool. It allows you to create protected spaces on your hard drive where you can put files and secure them with a password. There are two different methods used by this application. The first one creates a self-mounting encrypted space. When you use this method, Protect Files creates an ".app" file. You open it as you would open any application and you will be asked for the password that you typed in when you created it. If you enter it right, a finder window will appear, and you can drag and drop files into it or out of it, and work with files just like you would do on any Finder window. The second method creates an encrypted disk image. When you do that and open the image, it will be mounted on Finder, and it will be treated like any other volume. You can drag files into it, delete files, etc. Both methods are encrypted using AES-128 or AES-256. The first is secure enough and faster than AES-256. But if you need the extra security, it is nice to have it.
In short, Protect Files is a nice utility to password-protect your files. It has a nice interface and it works very well.