Noob question; Installing intellitronix digital gauge, (tw: LOTS OF DUMB QUESTIONS)

"Tachometer – Green wire – Connect the wire from the tachometer to the negative terminal of the coil or a direct tach output lead from your distributor or electronic control module. If you are using an aftermarket capacitive discharge ignition system, such as an MSD, you must use the designated ‘tach output’ connection on the electronic box. Do not make any connections directly to the coil with this type of system. With high output Ignition systems may also create frequency noise that may interfere with operation of gauges that may require a tachometer filter. If your vehicle has a HEI ignition, connect to the terminal marked ‘TACH’, or, on some systems, a single white wire with a spade terminal. If your vehicle has a magneto system, connect the tach signal wire to the negative side of the coil. Do not connect the tach terminal to the positive (+ or high voltage) side of the ignition coil or may need a Tachometer adapter for proper operation of your Digital Gauges."

I only understand some of these words... luckily for me the previous owner has an aftermarket tach with a green wire... So plug and play?