they are for distinctly different cartridges.
moving magnet is the traditional stereo cartridge that came after the old ceramic cartridges.
moving coil is a sub-category, the magnet is stationary, and the tiny coil moves. moving coil cartridges put out very low signals, they need to be amplified up to the strength of a moving magnet cartridge (thus your separate moving coil input.
after that, any phono signal needs to go thru a phono EQ circuit, to boost the lows and cut the highs and boost that equalized signal up to line level, the strength to be sent to the amp.
note: some modern TT, like mine, have an optional built-in phono preamp. I can send it's preamp's line level directly to an amp via ANY line level input (CD, AUX, ...). Or, not use it, use TT phono out, send the cartridge signal to my preamp's phono input, use my preamp's phono eq and signal boost.
note: many use a separate dedicated pre-pre amp for their moving coil cartridges, then, that is now the strength of a moving magnet cartridge, then send that off to phono EQ somewhere.
moving magnet is the traditional stereo cartridge that came after the old ceramic cartridges.
moving coil is a sub-category, the magnet is stationary, and the tiny coil moves. moving coil cartridges put out very low signals, they need to be amplified up to the strength of a moving magnet cartridge (thus your separate moving coil input.
after that, any phono signal needs to go thru a phono EQ circuit, to boost the lows and cut the highs and boost that equalized signal up to line level, the strength to be sent to the amp.
note: some modern TT, like mine, have an optional built-in phono preamp. I can send it's preamp's line level directly to an amp via ANY line level input (CD, AUX, ...). Or, not use it, use TT phono out, send the cartridge signal to my preamp's phono input, use my preamp's phono eq and signal boost.
note: many use a separate dedicated pre-pre amp for their moving coil cartridges, then, that is now the strength of a moving magnet cartridge, then send that off to phono EQ somewhere.