A stream is an unbounded sequence of events that go from producers to consumers. A lot of data is produced as a stream of events, for example financial transactions, sensor measurements, or web server logs.
Stream processing libraries, such as Streamz, help build pipelines to manage streams of continuous data, allowing applications to respond to events as they occur.
Stream processing pipelines often involve multiple actions such as filters, aggregations, counting, analytics, transformations, enrichment, branching, joining, flow control, feedback into earlier stages, back pressure, and storage.