fascia vs aponeurosis

fascia and aponeurosis both are nouns.

Word	Noun	Adjective	Verb	Adverb
fascia	Yes	No	No	No
aponeurosis	Yes	No	No	No

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

fascia: a sheet or band of fibrous connective tissue separating or binding together muscles and organs etc
aponeurosis: any of the deeper and thicker fascia that attach muscles to bones; resemble flattened tendons

fascia (noun)	aponeurosis (noun)
instrument panel on an automobile or airplane containing dials and controls	any of the deeper and thicker fascia that attach muscles to bones; resemble flattened tendons
a sheet or band of fibrous connective tissue separating or binding together muscles and organs etc