Here is a glossary of some of the terms you may come across when searching for a digital piano:
Action - The feel and response of the keyboard
Stereo Dynamic Stereo Sampling with Advanced Wave Memory (AWM) - AWM (Advanced Wave Memory) is a sampling system found in Yamaha digital pianos that creates the realism of an acoustic instrument by using digital technology to record the sound of the instrument and applying high quality digital filtering technology to the recorded audio samples. The waveform of sound created by playing the key of an acoustic piano differs depending on the force with which it is played, from pianissimo to fortissimo. AWM's Dynamic Stereo Sampling can produce these dynamic nuances by recording samples of different playing strengths. The greater the number of samples used, the greater the expression.
Damping pedal - A pedal that controls the damping of the piano strings. In the case of digital pianos, this pedal is connected to the back of the piano by a string.
Graduated Hammer Effect Keyboard (GHE) - This is a Yamaha-patented action keyboard that gives all keys real resistance that increases from the upper to lower registers, just like a real acoustic piano. This means you can naturally hit the thundering lows with your left hand and let your right fingers dance and fly with the highs.
Half Damper Effect - A feature unique to Yamaha digital pianos where the player can emulate a technique where the damper pedal (hash) is only partially depressed.
Metronome – A device used to mark the time by means of recurring ticks or flashes at adjustable intervals.
MIDI – refers to Musical Instrument Digital Interface: a standard protocol for communication between electronic musical instruments and computers.
Modulation Wheel or Modulation Wheel - One of the many continuous controls common to a MIDI device. It is often used to add a vibrato effect to a sound.
Number of Keys – Acoustic pianos traditionally have 88 keys. Some digital pianos have less than 88 keys for portability.
Pitch Bend Wheel – is a control on a pitch bend synthesizer (portamento) - to vary the pitch continuously.
Polyphony – This number determines how many notes can be heard at the same time in the digital piano.
USB - (Universal Serial Bus) is a technology that allows high-speed data transfer via cable. It is an alternative to Firewire. It is often used to connect keyboards, mice and portable data storage devices to computers.
Voice – Any unique sound that can be played on the keyboard is considered a voice. Strings, organ, harpsichord and piano are examples of voices. The more voices an instrument has, the wider the range of sounds it can produce.