A Buggy is an automobile with wheels that project beyond the vehicle body.
A dune buggy is a recreational vehicle with large wheels, and wide tires, designed for use on sand dunes or beaches. The design is usually a modified vehicle and engine mounted on an open chassis. The modifications usually attempt to increase the power to weight ratio by either lightening the vehicle or increasing engine power or both. Dune buggies designed specifically for operation on open sand are called sandrails.
A similar, more recent generation of off-road vehicle, often similar in appearance to a sandrail but designed for different use, is the "off-road go kart". The difference may be little more than fitting all-terrain tires instead of sand tires.