From initiates a never-ending read stream from a Source, and returns a pipeline for processing or passing to a different Source.

Pipeline allows us to take an input channel, and pass the messages through a Processor, and then pass into another Source for processing elsewhere.

Source is the interface which should be able to pull messages from a streaming source, and then also push to them, an example would be Redis Streams, Redis Blocking lists, Kafka, Kinesis, etc.