UML Class Diagram Relationships and Symbols
1. Inheritance
B inherits from A.
2. Realization
B implements A.
3. Association
A and B call and access each other’s elements.
4. Association (one way)
A can call and access B’s elements, but not vice versa.
5. Aggregation
A has a B, and B can outlive A.
6. Composition
A has a B, and B depends on A.