vendor vs dealer

vendor and dealer both are nouns.

Word	Noun	Adjective	Verb	Adverb
vendor	Yes	No	No	No
dealer	Yes	No	No	No

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

vendor (noun)	dealer (noun)
someone who promotes or exchanges goods or services for money	a firm engaged in trading
	a seller of illicit goods
	the person who distributes the playing cards in a card game
	someone who purchases and maintains an inventory of goods to be sold
	the major party to a financial transaction at a stock exchange; buys and sells for his own account