gas jet vs pilot light

gas jet and pilot light both are nouns.

Word	Noun	Adjective	Verb	Adverb
gas jet	Yes	No	No	No
pilot light	Yes	No	No	No

As nouns, pilot light is a hyponym of gas jet; that is, pilot light is a word with a more specific, narrower meaning than gas jet:

gas jet: burner such that combustible gas issues from a nozzle to form a steady flame
pilot light: small auxiliary gas burner that provides a flame to ignite a larger gas burner

Other hyponyms of gas jet include bunsen, bunsen burner, etna, gas ring, pilot, pilot burner.

gas jet (noun)	pilot light (noun)
burner such that combustible gas issues from a nozzle to form a steady flame	indicator consisting of a light to indicate whether power is on or a motor is in operation
	small auxiliary gas burner that provides a flame to ignite a larger gas burner