Off-road 4x4

Offroad 4X4
Four-wheel drive, 4WD, or 4x4 ("four by four") is a four-wheeled vehicle with a drive train that allows all four wheels to receive torque from the engine simultaneously. While many people associate the term with off-road vehicles and Sport utility vehicles, powering all four wheels provides better control than normal road cars on many surfaces, and is an important part in the sport of rallying. In abbreviations such as 4x4, the first figure is normally taken as the total number of wheels and the second is normally taken as the number of powered wheels (the numbers are actually axle-ends to allow for more than one wheel on each end of an axle). 4x2 means a four-wheel vehicle in which engine power is transmitted to only two axle-ends: the front two in front-wheel drive or the rear two in rear-wheel drive.

Big Dune Driving
Big dune Driving or Dune bashing involves driving over sand dunes with 4x4 offroad vehicles.

Overlanding is the self-reliant overland travel to remote destinations where the journey is the principal goal. Typically, but not exclusively, accommodated by mechanized off-road capable transport (from bicycles to trucks) where the principal form of lodging is camping; often lasting for extended lengths of time (months to years) and spanning international boundaries.
Source: Wikipedia