That can mean a simple peck on the lips, or a really deep, long kiss. I heard the noises. Groping--if only on a really light level--becomes involved.
Make out is just kissing And hook up is sex. I personally define making out as something I'm none too interested in, but also "heavy" kissing and just kissing. In fact, any simple skin-to-skin gestures that make you feel closer to your partner is considered making out. Making out to me means French kissing and hands all over. Difference between hooking up and making out?