Magazines and clips are not the same thing. They're different. But there is probably no more common misuse of terms in the handgun world than calling a magazine a clip. A magazine is (usually) a sheet steel box that holds cartridges in position for feeding in the magazine well of an autoloading pistol. I say “usually...sheet steel” because we are seeing polymer magazines more frequently these days.
A magazine is actually a part of the gun, in the sense that it has a follower and a spring. The first round to be loaded into the magazine rests against the follower and the next one rests against the first, etc. in order to form a column of cartridges. A magazine spring under the follower provides constant upward pressure on the column of cartridges. Loaded into a pistol, the magazine keeps the top cartridge in a position that will ensure proper feeding into the chamber when the pistol's slide cycles.
For some unknown reason, it has become popular to call magazines clips, which they aren't. Clips are also often made of sheet metal and they do hold cartridges. However, clips are not directly involved in feeding as part of the gun's operating cycle. The most common form of clip known to 21st Century handgunners is the half- or full-moon clip used to load and headspace automatic pistols cartridges in revolvers.
Usually, this is the venerable .45 ACP round. There is also a device called the stripper clip, which holds a column of cartridges by their rims. The shooter indexes the stripper clip into the top of a pistol's magazine well, then strips them off against the pressure of a magazine spring and follower mounted in the gun. A loading convenience, the pistol stripper clip is often used for the Mauser C96 pistol in America. Similar devices were once used on a variety of military rifles.
Clips are a different breed of cat than the magazine, although they are both concerned with ammunition and firearms.
