Relationships

Dependency

• Dashed arrow (<----)
• objects of a class work briefly with objects of another class

Association

• Simple line (-----)
• objects of one class know the objects of another class
• can be 1:1, 1:N, N:1, N:M

Aggregation

• Empty diamond line (<>----)
• has-a relationship

Composition

• Filled diamond line (<*>-----)
• part-of relationship

Inheritance

• Empty arrow (<|-----)
• is-a relationship