proxy vs power of attorney

proxy and power of attorney both are nouns.

Word	Noun	Adjective	Verb	Adverb
proxy	Yes	No	No	No
power of attorney	Yes	No	No	No

As nouns, power of attorney is a hypernym of proxy; that is, power of attorney is a word with a broader meaning than proxy:

proxy: a power of attorney document given by shareholders of a corporation authorizing a specific vote on their behalf at a corporate meeting
power of attorney: a legal instrument authorizing someone to act as the grantor's agent

proxy (noun)	power of attorney (noun)
a power of attorney document given by shareholders of a corporation authorizing a specific vote on their behalf at a corporate meeting	a legal instrument authorizing someone to act as the grantor's agent
a person authorized to act for another