An E14 lamp holder ring's primary use is to secure a lampshade to an E14-base light fixture, acting as a collar that screws onto the lamp holder's threaded base to shades firmly in place for table lamps, chandeliers, and wall lights, preventing them from slipping or tilting. These rings are essential for mounting shades and come with the lamp holder or are sold separately, allowing easy attachment and removal for maintenance or style changes.