Message channelabstracts communication between components. It does allow for sending and receiving messages. A message channel may follow either point-to-point or publish-subscribe semantics. With a point-to-point channel, only one consumer can receive each message sent to the channel. Publish-subscribe channels, broadcast each message to all subscribers on the channel.
Pollable channelsextends Message Channels with capability of buffering Messages within a queue. The advantage of buffering is that it allows for throttling the inbound messages and preventing of message loss.