The difference between a pillion pad and a passenger seat is comfort for the passenger. A pillion pad is a vintage-style motorcycle accessory and is simply a leather-upholstered pad located on the rear fender. This allows a passenger to sit with more comfort than if they were to sit on the fender itself. On some choppers the pillion pad (also known as a p-pad) is positioned to support the rider, should the rider slip back a bit on a sprung solo seat, for instance. A true passenger seat is full seat meant for regular use, and is similar in style and materials to the main seat. Typically it is part of a two-up motorcycle seat, that is, one seat that is designed and built for both the rider and a passenger.