There can be numerous types of ‘keys’ on a keyboard, whether it is for MIDI, workstation, or a synthesizer. Some other types include full-weighted, semi-weighted, or those with aftertouch.
Synth action keys are typically made of plastic and use springs to return the key back to it’s rested position. Other keyboards use weights for their make of keys.
One of the main features of a synth action keyboard is the lighter, quicker feel of the keys. Weighted keyboards are typically slower to return to it’s initial position. It all comes down to preference, such as what type of music is being played, what instruments the sounds are playing as opposed to piano.
Those who prefer “synth action”, as guessed, are musicians who play synthesizers because of it’s playability as well it being cheaper than other weighted keys.
