web page vs webpage

web page and webpage both are nouns.

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

As nouns, web page and webpage are synonyms defined as:

web page and webpage: a document connected to the World Wide Web and viewable by anyone connected to the internet who has a web browser

web page (noun)	webpage (noun)
a document connected to the World Wide Web and viewable by anyone connected to the internet who has a web browser	a document connected to the World Wide Web and viewable by anyone connected to the internet who has a web browser