backplate vs armor plating

backplate and armor plating both are nouns.

Word	Noun	Adjective	Verb	Adverb
backplate	Yes	No	No	No
armor plating	Yes	No	No	No

As nouns, armor plating is a hypernym of backplate; that is, armor plating is a word with a broader meaning than backplate:

backplate: plate armor protecting the back; worn as part of a cuirass
armor plating: specially hardened steel plate used to protect fortifications or vehicles from enemy fire

Other hypernyms of backplate include armor plate, armour plate, plate armor, plate armour.

backplate (noun)	armor plating (noun)
plate armor protecting the back; worn as part of a cuirass	specially hardened steel plate used to protect fortifications or vehicles from enemy fire