backhoe vs digger

backhoe and digger both are nouns.

Word	Noun	Adjective	Verb	Adverb
backhoe	Yes	No	No	No
digger	Yes	No	No	No

As nouns, digger is a hypernym of backhoe; that is, digger is a word with a broader meaning than backhoe:

backhoe: an excavator whose shovel bucket is attached to a hinged boom and is drawn backward to move earth
digger: a machine for excavating

Other hypernyms of backhoe include excavator, power shovel, shovel.

backhoe (noun)	digger (noun)
an excavator whose shovel bucket is attached to a hinged boom and is drawn backward to move earth	a machine for excavating
	a laborer who digs