barrier vs fencing

barrier and fencing both are nouns.

Word	Noun	Adjective	Verb	Adverb
barrier	Yes	No	No	No
fencing	Yes	No	No	No

As nouns, fencing is a hyponym of barrier; that is, fencing is a word with a more specific, narrower meaning than barrier:

barrier (noun)	fencing (noun)
a structure or object that impedes free movement	the art or sport of fighting with swords (especially the use of foils or epees or sabres to score points under a set of rules)
any condition that makes it difficult to make progress or to achieve an objective	a barrier that serves to enclose an area
anything serving to maintain separation by obstructing vision or access	material for building fences