Electronic control unit (ECU) belongs to which part of the car, what is the function?

Part of the electrical equipment ECU (Electronic Control Unit) electronic control unit, also known as the "car computer", "car computer" and so on. From the use of the car is a special microcomputer controller, also known as the car special microcontroller. It is the same as ordinary microcontroller, by the microprocessor (CPU), memory (ROM, RAM), input / output interface (I / O), analog-to-digital converter (A/D), as well as shaping, driving and other large-scale integrated circuits. The function of the electronic control unit is based on its memory program and data on the air flow meter and various sensors input information for computing, processing, judgment, and then output instructions to the injector to provide a certain width of the electrical pulse signal to control the amount of fuel injection. The electronic control unit consists of a microcomputer, input, output and control circuits.