title: Why is this ERD Entity one to many?
body: <p>This is my assignment: Now is your chance to create a full ERD from scratch. We would like you to create a web application that allows users to see a list of books (each with title and author name). Furthermore, the users should be allowed to save a list of their own favourite books.</p>
  
  <p>And the picture below is the solution.</p>
  
  <p><a href="https://i.stack.imgur.com/bx5UM.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/bx5UM.png" alt=""></a></p>
  
  <p>Looking at the solution, I can understand that one author can have written many books. And one book can be inside many favourites. But one user inside many favourites? Shouldn't users and favourites be a one to one relationship? One user has one favourites list?</p>