Thread: Spark Plugs

This may seem like a silly question, but I don't know much about mechanics. I remember my ex-husband 'gapping spark plugs' during a home tune up of our first car. Now the silly question .... do cars still have spark plugs? If not, what has replaced them?
Thanks for humoring me.

Cars that use diesel fuel do not have spark plugs. Cars that use gas still use spark plugs.

Cars need a spark plug to start the engine. It's connected with the ignition switch.

If I'm not mistaken, a car always have an spark plugs. As what mamabear had mentioned, it is important to run the car engine. Do you see the great use of an spark plugs in our car?