1. Association / Aggregation / Composition and inheritance

2. Association
Relationship where all object have their own lifecycle and there is no owner. Ex: Airplane and passengers. No ownership between the objects and both have their own lifecycle. Both can create and delete independently

3. Aggregation
Special form of Association where all object have their own lifecycle but there is ownership ( Has a relationship) and child object can not belongs to another parent object.
Ex: Department and teacher.
A single teacher can not belongs to multiple departments, but if we delete the department teacher object will not destroy.

4. Composition
Special form of Aggregation . Child object dose not have their lifecycle and if parent object deletes, all child object will also be deleted (ownership). Ex : Person and hands.

6. Inheritance : ”is” relationship
An employee is a person

7. Association
No ownership
Own lifecycle
Aggregation
Ownership ( has a..)
Composition
Ownership (composed of ..)
No Own lifecycle
Inheritance
Is relationship

8. Association
An association is usually represented as a data field in the class.

9. Representing Aggregation/composition in Classes
An aggregation / composition relationship is usually represented as a data field in the aggregated class.

10. Inheritance
Inheritance models the is-an-extension-of relationship between two classes.

11. Borrowing Loans
Name
Loan
Person
Borrower
Address