Slipping refers to the situation where the tire spins independently from the rim/wheel. Almost all bicycle braking systems are designed to stop the rim/wheel; the potential exists where above certain speed threshold, stopping the rim/wheel does not stop the momentum of the tire, thereby causing the tire to continue to rotate independently from the rim. Not only does tire slipping afford less control, but it also causes flats because as the tire and inner tube rotate independently from the wheel, the valve stem that's threaded through the wheel can rip.
Additional material extended from the bead that when inflated, the air pressure pushes the material onto the inner sidewall of the rim thereby increasing surface friction between the tire and the rim, helps to minimize tireslipping. Groove with Chamfered Verge Tread pattern with unique chamfered grooves that quickly guides water away from the tread's contact surface.