For those reading that may now be confused, the proper terminology for the part of a firearm which holds ammunition is the magazine (internal/removable/etc).
"Clip" is slang for magazine. However, "Clip" is proper when referring to the M1 Garand semi-auto rifle (from WWII/Korea) which uses an "Enbloc Clip" to hold 8 rounds. The 8 round enbloc clip is placed into the rifle, which sits into the internal magazine. Confused yet?
The M1 garand clip is discharge automatically from the rifle when the last round is fired. The rifle is then reloaded by inserting a new clip, etc.
Clip is also used when referring to ammuntion "stripper clips" which are strips of spring metal which hold ammuntion that is "stripped" off into the firearm's magazine (internal or external, both installed or remove from the firearm).