The follower is a part in a gun or firearm magazine which pushes the cartridges or rounds along, and “follows” them while doing so. It may push the ammunition upward, downward, backward, or forward.
Followers are most often made of metal or plastic, and are moved along their way by spring tension.
Whether a magazine is tubular or box-style, detachable or built-in, the follower is always the part of the magazine which moves the ammunition towards the gun’s breech so it will be ready to be loaded into the chamber when the time comes.
Clips do not have followers; ammunition does not move inside a clip except when it is pushed out of a stripper clip and into a magazine, usually by a shooter’s thumb.