obstruction vs barrier

obstruction and barrier both are nouns.

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

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

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

obstruction: something immaterial that stands in the way and must be circumvented or surmounted
barrier: any condition that makes it difficult to make progress or to achieve an objective

Other hyponyms of obstruction include roadblock, hang-up, hitch, rub, snag, hurdle, stymie, stymy.

obstruction (noun)	barrier (noun)
getting in someone's way	a structure or object that impedes free movement
the act of obstructing	any condition that makes it difficult to make progress or to achieve an objective
any structure that makes progress difficult	anything serving to maintain separation by obstructing vision or access
something immaterial that stands in the way and must be circumvented or surmounted
the physical condition of blocking or filling a passage with an obstruction