Message channels are the primary components that separate producers from consumers. This chapter explained the various message channels in detail. The channels that one should select depend on either P2P or Pub/Sub nature. In a P2P, only one consumer receives, while in a Pub/Sub model, all registered subscribers receive a copy of the message. In addition, Spring Integration provides a functionality for buffering the messages in order to avoid over-flooding the consumers. The various out-of-the-box implementations of channels cater to these characteristics.