A real-time data processing system may enter quickly changing data and produce results almost instantly, making it simple to observe changes over time in such a system. A radar system, for instance, relies on a constant stream of input data that is processed by a computer to reveal the location of various aircraft flying within the radar's range and then display it on a screen so that anyone viewing the screen can know the precise location of an aircraft at that precise moment.
Because it requires a constant stream of input data to produce the output needed at that precise instant, real-time data processing is also known as stream processing. The processing of online orders, making reservations and bookings online, and real-time fraud detection for credit cards are all good examples. The main advantage of real-time data processing is the instantaneous output from input data, which guarantees that everything is current. On the other side, batch processing results in data that is no longer timely.