internet site vs portal

internet site and portal both are nouns.

Word	Noun	Adjective	Verb	Adverb
internet site	Yes	No	No	No
portal	Yes	No	No	No

As nouns, portal is a hyponym of internet site; that is, portal is a word with a more specific, narrower meaning than internet site:

internet site: a computer connected to the internet that maintains a series of web pages on the World Wide Web; a computer connected to the internet that maintains a series of web pages on the World Wide Web
portal: a site that the owner positions as an entrance to other sites on the internet

Other hyponyms of internet site include chat room, chatroom, portal site, newsgroup, social networking service.

internet site (noun)	portal (noun)
a computer connected to the internet that maintains a series of web pages on the World Wide Web; a computer connected to the internet that maintains a series of web pages on the World Wide Web	a grand and imposing entrance (often extended metaphorically)
	a short vein that carries blood into the liver
	a site that the owner positions as an entrance to other sites on the internet