Actually, it's the opposite in firearms. Clips hold ammunition, whereas magazines feed ammunition as part of the firearms operation. Some magazines are removable, whole others are entirely internal.

Most automatic pistols use detachable magazines that lift the ammunition with a spring for feeding into the chamber, wheras double-action revolvers have speed-loading clips that hold ammo in a manner that lets you load the cylinder quickly.

The M1 garand has kinda a hybrid system where there's a clip that holds the ammunition and is inserted into the gun and is fed with the ammo, but is not a magazine.