Use case diagram

Use Case Diagram has been implemented based on system functions, each use case represents each function,

,,Present the archived message" use case is at the top of the diagram directly linked to the actor ,,USER".

This indicates a association relationship representing communication and interaction between the actor and the use case.

This relationship signifies that the actor is involved in the functionality described by the use case.

Other use cases are linked to the ,,Present the archived message" use case using Extend Relationship, since they are optional.

The Extend Relationship illustrates that a use case can be extended by another use case under specific conditions. It is represented by a dashed arrow with the keyword "extend." This relationship is useful for handling optional or exceptional behavior.