keyboard vs keypad

keyboard and keypad both are nouns.

Word	Noun	Adjective	Verb	Adverb
keyboard	Yes	No	No	No
keypad	Yes	No	No	No

As nouns, keypad is a hyponym of keyboard; that is, keypad is a word with a more specific, narrower meaning than keyboard:

keyboard: device consisting of a set of keys on a piano or organ or typewriter or typesetting machine or computer or the like
keypad: a keyboard that is a data input device for computers; arrangement of keys is modelled after the typewriter keyboard

Other hyponyms of keyboard include computer keyboard, clavier, fingerboard, piano keyboard, typewriter keyboard.

keyboard (noun)	keypad (noun)
holder consisting of an arrangement of hooks on which keys or locks can be hung	a keyboard that is a data input device for computers; arrangement of keys is modelled after the typewriter keyboard
device consisting of a set of keys on a piano or organ or typewriter or typesetting machine or computer or the like