Rolling friction, often referred to as rolling resistance, occurs when a sphere rolls over a surface, with contact points having zero velocity. This frictional force is relevant only when there is acceleration or sliding; if the sphere rolls without acceleration, friction is effectively zero. The sphere deforms at the contact point, shifting the normal force and contributing to rolling resistance. The discussion highlights the distinction between static and dynamic friction, noting that static friction can exist even when the wheel is not moving. Overall, rolling friction involves complex interactions at the microscopic level, influenced by surface deformation and torque.