The document discusses use case diagrams and provides examples. It explains that use case diagrams show actors and use cases to describe major services or functionality provided by a system. Examples given include:
- A hospital reception scheduling patient appointments, collecting information, allotting beds, and processing payments.
- An automated homework assignment system distributing assignments to students, collecting solutions, distributing grades and reminders.
- A university registration system allowing professors to indicate courses, printing catalogs, students selecting courses with constraints, and transmitting registration information to billing.