In some ways these words are used in the same places. I will try to explain the main differences. 1) Exchange an act of giving one thing and receiving another (especially of the same kind) in return. "We exchanged addresses" 2) Barter has the same meaning, except that with 'barter' you don't use money. With 'exchange', it could be money. ""he often bartered a meal for drawings" 3) Swap usually refers to exchanging something that is not the same thing. e.g. your friend is holding a teddybear you like, and you are holding a cat she likes, you say: "Let's swap."