finger vs digit

finger and digit both are nouns.

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

As nouns, digit is a hypernym of finger; that is, digit is a word with a broader meaning than finger:

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

Other hypernyms of finger include dactyl, extremity.

As nouns, finger and digit are synonyms defined as:

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

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

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

finger (verb)	digit (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