Illustrate the term Rolling with diagram

A pair of cylindrical rollers made of iron or steel rotate in opposite direction with a gap between them which is smaller than cross section of the piece that is to be rolled. Work piece is inserting into the gap and as it passes between rolls, it's squeezed, its cross section being progressively reduced. As the working volume remains constant, result of passing  through  the  rolls  would  be  lengthening  of  work  piece  and  a corresponding reduction and shaping of the cross section.

Rolling provides the most efficient and cheapest method of reducing the cross sectional area of a piece of the material in such a way that final thickness is uniform throughout long lengths of the product.

Rolling - Sheets of sheet, plate, strips of material of uniform thickness.