bucket vs vessel

bucket and vessel both are nouns.

Word	Noun	Adjective	Verb	Adverb
bucket	Yes	No	Yes	No
vessel	Yes	No	No	No

As nouns, vessel is a hypernym of bucket; that is, vessel is a word with a broader meaning than bucket:

bucket (noun)	vessel (noun)
a roughly cylindrical vessel that is open at the top	a craft designed for water transportation
the quantity contained in a bucket	an object used as a container (especially for liquids)
	a tube in which a body fluid circulates

bucket (verb)	vessel (verb)
carry in a bucket
put into a bucket