junk heap vs garbage heap

junk heap and garbage heap both are nouns.

Word	Noun	Adjective	Verb	Adverb
junk heap	Yes	No	No	No
garbage heap	Yes	No	No	No

As nouns, junk heap and garbage heap are synonyms defined as:

junk heap and garbage heap: an accumulation of refuse and discarded matter

Other synonyms of junk heap include junk pile, refuse heap, rubbish heap, scrapheap, trash heap, trash pile.

junk heap (noun)	garbage heap (noun)
an accumulation of refuse and discarded matter	an accumulation of refuse and discarded matter