An Access Control List (ACL) is a list of user permissions for a file, folder, or other object. It defines whether users and user groups can access the object and what operations they are allowed to perform on it. These operations typically include read, write, and execute.
ACLs provide a straightforward method of managing file and folder permissions. They are used by most operating systems, including Windows, Mac OS X, and Linux/Unix systems.
For example, if an ACL specifies read-only access for a specific user of a file, that user will be able to open the file, but cannot write, nor execute the file, thus not changing its contents.
While ACLs are typically hidden from the user, they can often be modified using a graphical interface. On Unix systems, ACLs can be edited using the