UML Sequence Diagram - Jessica00Oliveira/Flight-Booking-App GitHub Wiki

From the point of view of the sequence diagram, the user is the first active object and this user can either do the login if all the credentials are known or tell that forgot the password and wants it back. In case the user wants to login, the user send the credentials to the login page. This page in turn sends those credentials to the database that stores user information. The database responds and the user is either allowed to enter the site or not. In the sequence diagram, this is represented by an alternative that creates a frame around part of the sequence showing the choice between accepting or rejecting the user login information. If the user forgot the password, then this page acess the database, the user responds to the security question and the database responds with the user's password.