In rolling, work material is deformed by compressive forces between constantly spinning rolls.  In other words, metals are passed between spinning rolls and the force applied reduces the thickness of the material.  Both the metals’ shapes and internal structures are changed. You can compare this process to rolling dough with a pin.

Rolling is one of the most important manufacturing processes in the modern world. The large majority of all metal products produced today are subject to rolling at one point in their manufacture.