Streams, functional sequences of events over time.
Everything is a stream.
STREAMS Traditionally, the term stream was used in programming languages as an abstract object related to I/O operations such as reading a file, reading a socket, or requesting data from an HTTP server. For instance, Node.js implements readable, writable, and duplex streams for doing just this. In the RP world, we expand the definition of a stream to mean any data source that can be consumed.