The various data items managed within an information system are collected together in homogeneous groups called objects. A definition, a description and possibly some documentation are associated with each object.
Whenever an object is created, it is automatically added to the repository.
Objects can be described by components which may themselves be objects. This implies that there can be links between objects. For example, conceptual entities are described using a list of properties. Conceptual entities and properties are types of object.
Some of these object types are specific to the entity-relationship concept, whereas others are concepts introduced by Adelia.
Objects belong to a type.