debris vs rubble

debris and rubble both are nouns.

Word	Noun	Adjective	Verb	Adverb
debris	Yes	No	No	No
rubble	Yes	No	No	No

As nouns, debris and rubble are synonyms defined as:

debris and rubble: the remains of something that has been destroyed or broken up

Other synonyms of debris include detritus, dust, junk.

debris (noun)	rubble (noun)
the remains of something that has been destroyed or broken up	the remains of something that has been destroyed or broken up