The Link object provides a way to create relationships between two objects by using Head and Tail properties. The Head and the Tail can each be associated with a single instance of almost any class. For example, a link object can have the Head point to a folder and the Tail point to a document. This type of relationship is in contrast to the one-to-many nature of the RCR (Referential Containment Relationship) class, which requires that the Tail point to a single folder, while the Head can point to many containable objects (any combination of documents, folders, or custom objects).
You can view the Link object class in the administration console in the object store's
folder. Similar to other classes, the link class can be extended with subclasses and its properties can be examined and modified. An application typically subclasses the link class and restricts the types of objects that can be pointed to by the Head and Tail properties based on the requirements of the application.