Correct me if I'm wrong, but I understood a clip to be internal, a magazine to be external...
Today, a magazine is that box loaded with cartridges.
The clip basically is a cartridge clip for an M-1 Garand.
That's the simple version because my movie and dinner is on in a couple of minutes.
A magazine is the removable 'box' that is used to reload a pistol or some rifles. An empty magazine is removed and a full one popped in to replace it.
A clip is a metal strip that holds ammo that is 'stripped' off of the clip into an internal magazine. The military M-1 is typical of this style. The media commonly confuse the two. (but then they think an AR-15 is a machine gun also.)