news story vs article

news story and article both are nouns.

Word	Noun	Adjective	Verb	Adverb
news story	Yes	No	No	No
article	Yes	No	Yes	No

As nouns, article is a hypernym of news story; that is, article is a word with a broader meaning than news story:

news story (noun)	article (noun)
an article reporting news	one of a class of artifacts
	nonfictional prose forming an independent part of a publication
	(grammar) a determiner that may indicate the specificity of reference of a noun phrase
	a separate section of a legal document (as a statute or contract or will)

news story (verb)	article (verb)
	bind by a contract; especially for a training period