The Data flow diagram (DFD) for a tourism management system shows how administrators, users, tour guides, databases, and external services communicate with one another. Users can both schedule tours and make payments through the system, and administrators handle booking management and user account administration. Tour packages and transactions are stored in the database and retrieved upon request. The system uses third-party payment processors to enable smooth transaction processing. The tour guides access tour bookings that belong to their assigned tours. The DFD organizes the data flow within the system, which leads to efficient tour management.