favor vs approval

favor and approval both are nouns.

Word	Noun	Adjective	Verb	Adverb
favor	Yes	No	Yes	No
approval	Yes	No	No	No

As nouns, approval is a hypernym of favor; that is, approval is a word with a broader meaning than favor:

favor (noun)	approval (noun)
an act of gracious kindness	the formal act of approving
souvenir consisting of a small gift given to a guest at a party	a message expressing a favorable opinion
an advantage to the benefit of someone or something	a feeling of liking something or someone good
an inclination to approve	acceptance as satisfactory
a feeling of favorable regard