With Microsoft Active Accessibility, UI elements are exposed to clients as Component Object Model (COM) objects. These accessible objects maintain pieces of information, called properties, which describe the object's name, screen location, and other information needed by accessibility aids. Accessible objects also provide methods that clients call to cause the object to perform some action. Accessible objects that have simple elements associated with them are also called parents, or containers.
Accessible objects are implemented using Microsoft Active Accessibility's COM-based IAccessible interface. The IAccessible methods and properties enable client applications to get information about UI elements needed by users. For example, IAccessible::get_accParent returns an interface pointer to an accessible object's parent, and IAccessible::accNavigate provides a means for clients to get information about other objects within a container.
For more information about how accessible objects and simple elements are related, see Simple Elements.