What is an Access Control List, or ACL ?
An access control list (ACL) is an attachment to a file, directory, or other object that provides information about permissions associated with the object. If there is no access control list, anyone can interact with the object and do anything with it. If a list is present, however, access and activities are limited to people on the list and the abilities of individual users may be restricted at different levels. The list can specify users, roles, or groups. Users are individual users who are registered in the system, such as an office network. Roles are titles that are assigned to people. For example, a user might have the role System Administrator. When an access control list restricts access to certain roles, only people in those roles will be able to manipulate the object. Groups are collections of users who are registered together, such as Secretarial Pool. Access control lists can determine who is allowed to view, edit, delete, or move an object. This can be useful on a security
