When working on machines, you get to know all the parts of the whole. You learn the function of the belts, pulleys and housings, you get to know the fluids that are needed to make the machine work and you also bet to know the heart of the machine.
Just like any human, a machine has a heart. This heart is not meaty and does not beat in time with the pumping of the blood. This heart is an engine, an electrical engine. These engines are mechanical hearts within the body of the machine. And this is just as well as a human heart. It pumps fluids in and out, it provides life to the machine and if it is badly damaged, it will die…just as the human body also dies.