The first camera I bought, back in 1969, was an Agfa Isomat Rapid, like this one. This was an automatic exposure camera which used 35mm film in Agfa Rapid cassettes. It produced 24mm x 24mm pictures. The cassette has a tongue on it, which sets the film speed for the light meter, and film is fed to an empty cassette on the wind side. Agfa film, and rapid cassettes are long gone, but if you have empty cassettes they can be loaded with bulk film; these days, who would?
I do have other cameras!