ACL
full spelling ： Access Control List
An Access Control List (ACL) is a list of permissions attached to an object that contains the basic and extended permissions that control access to a file. It specifies what access privileges users have to a directory. ACL specifies the right to lookup, insert, delete, read, write, lock, or administer files in a directory.
Microsoft Windows NT/2000, Novell's NetWare, and Unix-based systems are among the operating systems that use access control lists. In Windows NT/2000, an access control list (ACL) is associated with each system object. Each ACL has one or more access control entries consisting of the name of a user or users. The system administrator or the object owner creates the access control list for an object.