Pure rolling involves two surfaces moving over each other without sliding (sliding page), there Pure sliding occurs when one surface moves over another without rolling (rolling page). There are scenarios where this is partially rolling or conversely partial sliding in a rolling contact (rolling page). Usually one surface is fixed/stationary and the other move/slides, load can be applied on the stationary, but also on the moving surface. Sliding can also involve both surface moving, as long as there is a difference in velocity, small differentials are common referred to as ‘slip’.