What is grappling?

Bunch of guys getting "Handsy" with each other.

Grappling can be any number of martial arts that include grabbing, throwing, joint locks (finger, hand, elbow, shoulder, knee ankle manipulation) and  pressure points.

The difference is it doesn't concentrate on the strikes with hands or feet in as much as it is design for control of the opponent and submission to rendering unconscious.

Off the top of may head, Brazilian jiu jitsu, Japanese jiu jitsu, aiki jiu jitsu, Aikido, Judo, Hapkido, Greco Roman Wrestling,  . . . Etc