What is real-time processing?

Real-time processing, or real-time computing, is the term used for a processing system that needs to be complete within a fixed time frame. Real-time processing does not have to be fast in systems such as traffic lights where there is a set time between each instruction.

In a car's engine control unit, the system must be fast in order to take into account all of the variables at a particular moment and react appropriately. As long as the system has enough time to process the inputs and then make the appropriate outputs, it can be considered a real-time system.