gas jet vs pilot burner

gas jet and pilot burner both are nouns.

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

As nouns, pilot burner is a hyponym of gas jet; that is, pilot burner 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 burner: 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 light.

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