dedication vs subject matter

dedication and subject matter both are nouns.

Word	Noun	Adjective	Verb	Adverb
dedication	Yes	No	No	No
subject matter	Yes	No	No	No

As nouns, subject matter is a hypernym of dedication; that is, subject matter is a word with a broader meaning than dedication:

Other hypernyms of dedication include content, message, substance.

dedication (noun)	subject matter (noun)
the act of binding yourself (intellectually or emotionally) to a course of action	content communicating a message; what something is about
complete and wholehearted fidelity
a short message (as in a book or musical work or on a photograph) dedicating it to someone or something
a message that makes a pledge
a ceremony in which something (as a building) is dedicated to some goal or purpose