What is the difference between a keyboard and a digital piano?

'Keyboard' is a general or generic term for anything that will resemble a paino keys' layout. Be it a small child's or beginner's, to a full grand piano. Electric, digital, controller, a synthesizer or... 'acoustic' spinets, consoles, uprights, baby, parlor or concert grands.

Digital pianos are just that, offering up the full 88's (keys) of verisitility to simulate a full piano (and orchestra) keyboard range. One doesn't need a full 88 just to learn to play piano in the beginning.

As digital keyboards are of having of (usually) 49, 61 and 76 keyboard numbers in layouts.

Before digital, there were the 'electric' pianos and these gave a distictive 'punch' sound that can now be simulated (along with other piano effects) through digital in-programming of the units that are concidered as being 'musical devices'. Thus, the abbreviated term MIDI had come about.

And 'real' pianos, made of steel and wood, are more expensive in affordability if not not even close to being portable or all that space saving. But, the real thing can be so impressive.

Also, the keyboard can be referred to as a 'manual' or deck. As there can be multiple decks (manuals, as many as five banks) for a theatre or church organ. As too, reference to 'decks' for more than one digital unit to play on, but separate from each unit as according to the player's preferences.

To answer why a keyboard player needs more than one (digital keyboard) during a performance. Just an offshoot of what a big theatre organ was, and is still, capable of. This is 'presets' and programming coming into play.

price

the sound i think