- The basic modeling primitives are the object and the literal. Only an object has a
unique identifier.
- Objects and literals can be categorized into types. All objects and literals of a given type
exhibit common behavior and state. A type is itself an object. An object is sometimes
referred to as an instance of its type.
- Behavior is defined by a set of operations that can be performed on or by the object.
Operations may have a list of typed input/output parameters and may return a typed
result.
- State is defined by the values an object carries for a set of properties. A property may
be either an attribute of the object or a relationship between the object and one or
more other objects. Typically, the values of an object’s properties can change over time.
- An ODMS stores objects, enabling them to be shared by multiple users and applications.
An ODMS is based on a schema that is defined in the Object Definition Language
(ODL), and contains instances of the types defined by its schema.