Midi Keyboard: A musical keyboard (piano keys) that connects to the computer. It does not produce sound on its own, but sends a signal to "play" digital instruments (piano, synth, strings) within your music production software.
Midi Controller: Devices with buttons, faders (sliders), or drum pads (square pads). They are used to control volumes, mix, or play rhythms and beats more naturally than with a mouse.
Midi Interface: A bridge device (adapter) that allows you to connect older, classic musical instruments and synthesizers (which have the old 5-pin MIDI ports) to your modern computer via USB.
