A Passenger Service System or PSS is a network of software applications that help airlines manage all the passenger-related operations from ticketing to boarding.
Generally the PSS is made up of modules that are used to manage different parts of the airline’s business.
It contains information on schedules and fares and contains a database of reservations (or passenger name records) and of tickets issued (if applicable).
The DCS is used to enter information required by customs or border security agencies and to issue the boarding document.
In addition the DCS may also be used to dispatch cargo and to optimize aircraft weight and balance.