What is the engine control unit?

Some have called it the brain of the engine. And rightly so: the ECU (Engine control unit) or ECM (Engine control module), or the engine management control units, are in fact the nerve center that oversees every aspect of its operation, both in petrol and diesel engines (and also in hybrids). In other words, the ECU takes information from a multitude of sensors on board the car, processes it second by second and sends a series of commands to the peripheral actuators to make the engine work according to the strategy planned during the design phase.