In cabinets, these are These rails are mounted on the sides or beneath the drawer box to reduce friction when opening or closing the compartment. Drawer slides not... More that have hydraulic mechanisms the regulate the closing of the drawer so that it slows down before it closes.
Soft close drawers not only are silent, but they reduce the impact of the drawer hitting the cabinet frame to reduce wear on the cabinet. The mechanism also helps close the compartment all the way. The soft-close slides are sometimes called soft-close glides because of the smooth, gliding motion the drawer makes as it closes.