digit vs finger

digit and finger both are nouns.

Word	Noun	Adjective	Verb	Adverb
digit	Yes	No	No	No
finger	Yes	No	Yes	No

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

digit: a finger or toe in human beings or corresponding body part in other vertebrates
finger: any of the terminal members of the hand (sometimes excepting the thumb)

Other hyponyms of digit include minimus, toe.

As nouns, digit and finger are synonyms defined as:

digit and finger: the length of breadth of a finger used as a linear measure

Other synonyms of digit include finger's breadth, fingerbreadth.

digit (noun)	finger (noun)
a finger or toe in human beings or corresponding body part in other vertebrates	one of the parts of a glove that provides covering for a finger or thumb
one of the elements that collectively form a system of numeration	any of the terminal members of the hand (sometimes excepting the thumb)
the length of breadth of a finger used as a linear measure	the length of breadth of a finger used as a linear measure

digit (verb)	finger (verb)
	indicate the fingering for the playing of musical scores for keyboard instruments
	feel or handle with the fingers
	search for on the computer
	examine by touch