television vs receiving system

television and receiving system both are nouns.

Word	Noun	Adjective	Verb	Adverb
television	Yes	No	No	No
receiving system	Yes	No	No	No

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

television: an electronic device that receives television signals and displays them on a screen
receiving system: set that receives radio or tv signals

Other hypernyms of television include receiver.

television (noun)	receiving system (noun)
a telecommunication system that transmits images of objects (stationary or moving) between distant points	set that receives radio or tv signals
an electronic device that receives television signals and displays them on a screen
broadcasting visual images of stationary or moving objects