A booking generally contains information such as the date of booking, the user who booked it, and a date of commencement of the travel. A journey contains information about the flight code. Other information about the journey such as the departure and arrival time, and the source and destination cities can be evaluated on the basis of the flight which the journey is being undertaken. Both booking and journey will have their own specific IDs to identify them uniquely. Passenger information related to the booking must have the name of the passengers at the very least, but more commonly will have more information such as the age, gender, and e-mail.

A rough model of the Booking, Journey, Passenger, and User looks like this:

Figure 4.1: Bookings ecosystem