The term Electronic Keyboards covers a multitude of keyboard instruments and instrument types, but is generally accepted as meaning the modern style of portable keyboard or synthesizer along with musical workstations. Portable electronic keyboards are generally lightweight with a plastic casing and on-board speakers, synthesizers are usually a much more substantial instrument with a multitude of parameters that can be adjusted to create specific 'synthetic' or emulated sounds.
Music workstations are a more recent category and could be defined as digital electronic keyboards that have the on board capacity to record sequences of music and can thereafter process the recorded sounds. With perhaps the exception of some portable keyboards (that can operate for short periods on battery power) all of the aforementioned keyboards will only operate when connected to 240v mains power and can therefore be classed as electronic keyboards.
