charcoal pile vs heap

charcoal pile and heap both are nouns.

Word	Noun	Adjective	Verb	Adverb
charcoal pile	Yes	No	No	No
heap	Yes	No	Yes	No

As nouns, heap is a hypernym of charcoal pile; that is, heap is a word with a broader meaning than charcoal pile:

charcoal pile: a pile of wooden billets, covered with turf or moistened clay, used to produce wood charcoal.
heap: a collection of objects laid on top of each other

Other hypernyms of charcoal pile include agglomerate, cumulation, cumulus, mound, pile.

charcoal pile (noun)	heap (noun)
a pile of wooden billets, covered with turf or moistened clay, used to produce wood charcoal.	a car that is old and unreliable
	a collection of objects laid on top of each other
	(often followed by `of') a large number or amount or extent