Most engineered wood floors are created with a top surface that is a smooth composite, and a solid core. Unlike solid wood floors, these engineered wood floors can be sanded to get rid of scratches and stains while maintaining the factory finished surface. Take care when sanding an engineered wood floor as you want to avoid stripping the top layer off or removing the entire top layer because most older engineered wood floors can be sanded and re-finished to perfection.
However, some engineered wood floors cannot be refinished and this is largely due to the thickness of the top layer.