A lot of things can be classified as off-road clubs, though generally speaking, an off-road club is a semi-formal organization of off-roading enthusiasts who meet and participate in events. Off-road clubs often go out on group off-roading trips, go camping, and participate/host shows.
Off-road clubs are usually free of membership fees, though some have a small recurring charge. They sell and give away branded merchandise, make videos, set up forums, and host swap meets for parts, vehicles, and accessories.