Difference between OODM and CDM

1. Object-Oriented Data Modeling (OODM) :
In OODM, both the data and or their relationship is organized or contained in a single structure known as object. Object includes the information about the relationship between the facts within the object, as well as information about its relationship with other objects. It is also said to be Semantic Data Model.

An object is the abstraction of the real world entity and an object represents only one occurrence of entity.

Characteristics of OODM :

• It supports the representation of complex objects.
• It supports encapsulation.
• It exhibit inheritance.
• It supports the notion of object identity.

Example :
Shape, Circle, Rectangle and Triangle. Circle has the attributes Center and Radius. Triangle has the attributes Base and Height etc.

2. Conceptual Data Model (CDM) :
It identifies the highest-level relationship between the different entities. This model is the most abstract form of data model. It is helpful in communicating the ideas to a wide range of stakeholders because of its simplicity.

Features of CDM :

• It includes the important entities and the relationship among them.
• No attributes is specified.
• No primary key is specified.

Example :
Entity relationship model, which uses main concepts like entities, attributes and relationships.

Difference between OODM and CDM :

OODM	CDM
Stands for Object-Oriented Data Modeling.	Stands for Conceptual Data Modeling.
It has object and object includes behavior.	It has no object.
Both the data and or their relationship is organized or contained in a single structure known as object.	It identifies the highest-level relationship between the different entities.
It is an instance of an object.	It has entity.
Inheritance includes both state and behavior.	It does not include state and behavior.
It has a concept of Message.	No corresponding concept in CDM.
Encapsulation is present in OODM.	No such concept is present in CDM.
It has attributes like triangle has the attributes Base and Height is the example of OODM.	Entity relationship model, which uses main concepts like entities, attributes and relationships are the examples of CDM.