Digital Pianos are unlike keyboards or synthesisers, but are focused on emulating an acoustic piano.
The keys are standard size, typically full 88 note / 7.25 octave and will offer ‘touch sensitive’ and ‘weighted keys’.
The piano tone is sampled from a real acoustic piano and the various sensors within the key detect the key speed to trigger a tonally appropriate sample (step sampling) and dynamic volume.
Integral speakers and amplification produce the digital piano tone with volume control and headphones will be usable for silent practice.
Most will offer a small range of ‘voices’ useful to a piano player, such as e-pianos, harpsicord, organ and strings.
The tone response relative to key speed may be adjusted in the ‘touch sensitivity’ parameters.