spring mattress vs mattress

spring mattress and mattress both are nouns.

Word	Noun	Adjective	Verb	Adverb
spring mattress	Yes	No	No	No
mattress	Yes	No	No	No

As nouns, mattress is a hypernym of spring mattress; that is, mattress is a word with a broader meaning than spring mattress:

spring mattress: a mattress containing springs in a rigid frame
mattress: a large thick pad filled with resilient material and often incorporating coiled springs, used as a bed or part of a bed

spring mattress (noun)	mattress (noun)
a mattress containing springs in a rigid frame	a large thick pad filled with resilient material and often incorporating coiled springs, used as a bed or part of a bed