(Association)
Association in Java defines the connection between two classes that
are set up through their objects. Association manages one-to-one,
one-to-many, and many-to-many relationships. In Java, the multiplicity
between objects is defined by the Association. It shows how objects
communicate with each other and how they use the functionality and
services provided by that communicated object.
In Java, two types of Association are possible:
1) IS-A Association (is also referred to as Inheritance)
2) HAS-A Association
a) Aggregation
b) Composition