homepage vs webpage

homepage and webpage both are nouns.

Word	Noun	Adjective	Verb	Adverb
homepage	Yes	No	No	No
webpage	Yes	No	No	No

As nouns, webpage is a hypernym of homepage; that is, webpage is a word with a broader meaning than homepage:

homepage: the opening page of a web site; also, the first page opened when a web browser is launched (default or start-up page)
webpage: a document connected to the World Wide Web and viewable by anyone connected to the internet who has a web browser

Other hypernyms of homepage include web page.

homepage (noun)	webpage (noun)
the opening page of a web site; also, the first page opened when a web browser is launched (default or start-up page)	a document connected to the World Wide Web and viewable by anyone connected to the internet who has a web browser