web page vs homepage

web page and homepage both are nouns.

Word	Noun	Adjective	Verb	Adverb
web page	Yes	No	No	No
homepage	Yes	No	No	No

As nouns, homepage is a hyponym of web page; that is, homepage is a word with a more specific, narrower meaning than web page:

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

Other hyponyms of web page include home page.

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