Years ago, I bought a two-seat convertible — it was a great car, and a ton of fun to drive. But after I’d had it about a year it started turning off — just out of the blue. After making certain it was mechanically as close to perfect as it could be, I focused on the electronics and managed to identify a faulty fuel-pump relay, a small electronic circuit. I replaced it and the car ran beautifully.
That was my first practical introduction to electronic circuitry — not the actual mechanism — as the culprit.
The idea that mechanical action — turn the wheel, step on the gas, pull on the stick, adjust the throttle — doesn’t actually do anything physical but instead constitutes an input to an electronic system which then interprets that input and in turn initiates mechanical action, is known as “fly-by-wire,” as it was first introduced in aircraft.