Forgot the belt fed clips too lol.
"Magazine" is French for storehouse or storage place. The "storage places" for cartridges in firearms in general are called "magazines," whether they are detachable—as in the detachable box magazines generally found in automatic pistols—or fixed. The Mauser C96's magazine, for example, is filled by stripping rounds into the magazine from a stripper clip. The Garand's magazine is filled by inserting an "en bloc" (there's that French again, just what it sounds like, "in block form") clip of eight cartridges.
Incidentally, "clips" are not "magazines." When we refer to, say, an M16's "30-round clip" what we really mean is "30-round magazine," which is shorthand for "30-round detachable box magazine," the full and correct description.