text file vs web page

text file and web page both are nouns.

Word	Noun	Adjective	Verb	Adverb
text file	Yes	No	No	No
web page	Yes	No	No	No

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

text file: (computer science) a computer file that contains text (and possibly formatting instructions) using seven-bit ASCII characters
web page: a document connected to the World Wide Web and viewable by anyone connected to the internet who has a web browser

Other hyponyms of text file include webpage, ASCII text file.

text file (noun)	web page (noun)
(computer science) a computer file that contains text (and possibly formatting instructions) using seven-bit ASCII characters	a document connected to the World Wide Web and viewable by anyone connected to the internet who has a web browser