web tv vs television

web tv and television both are nouns.

Word	Noun	Adjective	Verb	Adverb
web tv	Yes	No	No	No
television	Yes	No	No	No

As nouns, television is a hypernym of web tv; that is, television is a word with a broader meaning than web tv:

web tv: the genre of original television content produced for broadcast via the World Wide Web.
television: broadcasting visual images of stationary or moving objects

Other hypernyms of web tv include telecasting, TV, video.

web tv (noun)	television (noun)
the genre of original television content produced for broadcast via the World Wide Web.	a telecommunication system that transmits images of objects (stationary or moving) between distant points
	an electronic device that receives television signals and displays them on a screen
	broadcasting visual images of stationary or moving objects