- In this system, there are 2 users who could login/sign up
- The Admin User and the Customer User
- The admin mainly for now just adds books to system
- The user can read 1 book at a time, but have history of his sessions
- During a session, the user can browse the book pages or end the session
- The admin users are already added to the memory (database)
- So no sign up for the admins
- There are initially some books (but admin can add books)
- In general, assume the user is behaving properly