website vs portal site

website and portal site both are nouns.

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

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

website: 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 site: a site that the owner positions as an entrance to other sites on the internet

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

website (noun)	portal site (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 site that the owner positions as an entrance to other sites on the internet