Can anyone explain how to connect laptop to car stereo to enjoy movie to a person who has very limited?

electronic knowlege? pls make it as simple as possible and minimize those cable jargons. pretend you are teaching a person who just woke up after being in coma since 70's. can you make it "dummy" or "idiot" version otherwise it's not gonna make any sense to me. can you kind enough to tell me exactly what i need to buy and typical cost? thanks so much.