The first uses a simple on/off switch, the ignition points, to provide properly timed pulses of 12-volt electricity to the ignition coil ... light to the No. 1 plug wire. Start the engine ...

The coil takes ... add-on inductive ignition boxes. Capacitive discharge (CD) systems, usually designed around an add-on CD box, have an internal transformer to step up 12-volt battery voltage ...

the High Energy Ignition (HEI to you and me). Its best feature was simplicity. The coil was contained within the distributor cap and it required the connection of only a single 12-volt wire.