It refers to the frame, engine,front and rear axles, springs, steering systems and the fuel tank bolted directly to the body-in short everything but the body.
Concept cars are typically a one-off thing for car shows, and not put into production for sale to the public, whereas a car which is put into production for sale to the public would be a production...
a cars chassis is underneath and keeps the body, suspension and wheels all attached together. if the chassis wasn't there the car would flop about and eventually either crash or fall apart. Daniel...