Objects and Containers
The type of ACL used for an object depends on whether the object is a simple object or a container. Containers are objects that hold other objects. The objects they hold can themselves be either simple objects or container objects. Simple objects do not hold other objects. Although any DCE component can have objects and containers, the simplest and most common illustration is the file system. In the file system, there are files and directories. The files are simple objects, and the directories are containers. The directories can hold simple objects (files) and other containers (subdirectories).
The Object ACL is associated with simple and container objects. The Initial Container and Initial Object ACLs are associated only with container objects.