There are two main types of cartridges: moving magnet (MM) and moving coil (MC). MM cartridges are more common, affordable, and compatible with a wide range of turntables. They typically offer a warm, detailed sound and are easier to replace. MC cartridges, on the other hand, are known for their higher fidelity and lower distortion but are often more expensive and require a compatible phono preamp or step-up transformer. Choosing the right cartridge depends on factors like budget, system compatibility, and sonic preferences.