A polite term for one's older brother; also used respectfully to refer to someone else's older brother.
お兄さんは何歳ですか？
How old is your older brother?
田中さんのお兄さんは医者です。
Mr. Tanaka's older brother is a doctor.
お兄さん、荷物を持ちましょうか。
Brother, shall I carry your luggage?
Used to address or refer to a young man (e.g., a stranger, shop assistant) or as a casual form of address to a male peer; often used vocatively.
あの、お兄さん、道を教えてください。
Excuse me, sir, could you tell me the way?
お兄さん、ビール一杯ください。
Hey man, one beer please.
お兄さん、写真撮ってもらえますか？
Hey, could you take a photo for us?