brokerage vs business concern

brokerage and business concern both are nouns.

Word	Noun	Adjective	Verb	Adverb
brokerage	Yes	No	No	No
business concern	Yes	No	No	No

As nouns, business concern is a hypernym of brokerage; that is, business concern is a word with a broader meaning than brokerage:

brokerage: the business of a broker; charges a fee to arrange a contract between two parties
business concern: a commercial or industrial enterprise and the people who constitute it

Other hypernyms of brokerage include business, business organisation, business organization, concern.

brokerage (noun)	business concern (noun)
place where a broker conducts his business	a commercial or industrial enterprise and the people who constitute it
a stock broker's business; charges a fee to act as intermediary between buyer and seller
the business of a broker; charges a fee to arrange a contract between two parties