Chmod is the OS X (Unix) Terminal command for manipulating file permissions and whether a file can be executed or not. You can learn more about Chmod, file permissions, and ACL here (for something clear and simple) and here (for something more detailed and technical).
For the most part, Chmod is fairly straight forward and easy to work with. But it does mean digging around in Terminal, and that’s not everyone’s cup of tea, or even if it is there may be times when it’s nice to just make those Chmod changes via the nice OS X graphical user interface (GUI).
BatChmod to the rescue
It has three major functions:
1) Change file/folder permissions without Terminal. Along with executable status and the Access Control List (ACL) that is often set on files and folders.
2) Unlock files/folders/disks you’ve lost access to. This is typically an ACL issue, and BatChmod will let you change those settings to something that restores your access.
3) Empty stubborn files from the Trash can. Sometimes you may find you can’t empty the Trash can because a stubborn file digs its heals in and refuses to go. Finder might report the file is in use. BatChmod gives a way to force empty the Trash can. Voila, stubborn files be gone!