cable railway vs railway system

cable railway and railway system both are nouns.

Word	Noun	Adjective	Verb	Adverb
cable railway	Yes	No	No	No
railway system	Yes	No	No	No

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

cable railway: a railway up the side of a mountain pulled by a moving cable and having counterbalancing ascending and descending cars
railway system: line that is the commercial organization responsible for operating a system of transportation for trains that pull passengers or freight

Other hypernyms of cable railway include railroad, railroad line, railway, railway line.

cable railway (noun)	railway system (noun)
a railway up the side of a mountain pulled by a moving cable and having counterbalancing ascending and descending cars	line that is the commercial organization responsible for operating a system of transportation for trains that pull passengers or freight