A single DCE object can have multiple ACLs, each of a different ACL type. The types of ACLs that are used for an object depend on whether the object is a simple object or a container. Simple objects, the most common kinds of objects, do not hold other objects. Containers are objects that hold other objects. The objects they hold can themselves be either simple objects or container objects. For example, in a 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).