In this section we will discuss a very important topic about relationships.

What do you understand by a Relationship? What are relationships all about?

To explain this we need to get back to the topic wherein we discussed about the prerequisites for any object to interact with any other object.

We know that the prerequisites are:-

  • The target object should exist.

  • The calling object should know the "address" of the target object.

  • The calling object should know the "type" of the called object.

  • The calling object should be related to the called object.

For objects to interact with each other there has to be some kind of interrelationship between them. Unrelated objects do not interact with each other.

That is what we will now discuss.

Relationships are very fundamental for objects to interact with each other to give different behaviours.

Now let's talk about the different types of relationships.

What are the different kinds of relationships that you can see between different systems in the World?


What are the fundamental building blocks between relationships in this world?

There are 3 fundamental relationships between systems.

Parent-Child relationship
Whole-Part relationship
Association relationship

Every other relationship that you come across is some variant of these 3 relationships. These are the 3 basic relationships that can exist between systems in this world.

Let's discuss each of these relationships in detail, the pros and cons and the best practices for each one of them.

Hemant Jha
Founder - VPlanSolutions
Researcher, Trainer