The term drop shot is for a type of fishing where you drop an artificial lure, usually soft plastic, over the side of a boat to the ground and then vigorously let it up and down until the big fish grabs the hook. We however wrongly call spinning with a soft plastic "drop shot". The art lies in making that little plastic look like a fish that has been hurt and thus an easy pray for the big fish.
The rig we usually use is a light jig-head and plastic fish.