(A)    A slab door is a door having no jamb material attached to it, no holes bored in it or hinges attached. This could be almost any style door ( Raised Panel , Flat Panel , French Doors with Glass , Solid or Hollow, wood , Steel , Fiberglass ) It’s just a rectangular Slab of material. It would normally be used for a pocket door ,or by-pass doors. And a pre-hung door would have a jamb , bored holes & hinges on it.