Porcelain tiles have a glaze(layering) of a glassy material over them. This makes them as strong as the glaze material and protects from scratches. These are less expensive and less durable then the vitrified tiles.Vitrified tiles are prepared by creation of 'glass phase inside the tiles'. In other words, they have glassy stuff inside then. This gives then more strength and durability. They are expensive also.
JYOTI
AR& INTERIOR DESIGNER