lightbulb vs electric lamp

lightbulb and electric lamp both are nouns.

Word	Noun	Adjective	Verb	Adverb
lightbulb	Yes	No	No	No
electric lamp	Yes	No	No	No

As nouns, electric lamp is a hypernym of lightbulb; that is, electric lamp is a word with a broader meaning than lightbulb:

lightbulb: electric lamp consisting of a transparent or translucent glass housing containing a wire filament (usually tungsten) that emits light when heated by electricity
electric lamp: a lamp powered by electricity

lightbulb (noun)	electric lamp (noun)
electric lamp consisting of a transparent or translucent glass housing containing a wire filament (usually tungsten) that emits light when heated by electricity	a lamp powered by electricity