A flat sheet of paper typically has more air resistance compared to a paper airplane when both are in motion through the air. This is because the flat sheet of paper presents a larger surface area directly against the airflow, creating drag as it moves through the air.
On the other hand, a paper airplane is designed to be aerodynamic, with a shape that reduces air resistance and allows it to glide more efficiently. The wings and overall shape of the airplane help to create lift and reduce the drag compared to a flat sheet of paper.
In summary, while both objects will experience air resistance, the flat sheet of paper generally has more drag when moving through the air compared to a paper airplane.