How does Akka Streams differ from Akka Actors?

Akka Streams and Akka Actors are both parts of the Akka toolkit, but they serve different purposes and address different programming paradigms. Here’s a detailed comparison of the two:

Purpose and Focus :
  1. Akka Actors:

    • Designed for message-driven concurrency and distributed systems.
    • The core concept is an actor, which encapsulates state and behavior, processes messages asynchronously, and communicates with other actors via message passing.
    • Focuses on managing complex, concurrent workflows using actor-based programming.
  2. Akka Streams:

    • Built on top of Akka Actors but focuses on stream-based, reactive data processing.
    • Provides a declarative, composable API for working with data streams (e.g., processing, transforming, and handling backpressure).
    • Focuses on efficiently managing data flow in a pipeline-like manner.
Programming Model :
Akka Actors :
* Uses the actor model.
* Developers define actor behavior by implementing the receive method or similar constructs.
* State is managed within each actor, and operations are triggered by incoming messages.

Example :
class MyActor extends Actor {
  def receive: Receive = {
    case msg: String => println(s"Received message: $msg")
    case _           => println("Unknown message")
  }
}?

Akka Streams :
* Based on the Reactive Streams specification.
* Developers define flows, sources, and sinks to create a stream processing pipeline.
* Handles backpressure automatically to control the rate of data flow.

Example :
val source = Source(1 to 10)
val sink = Sink.foreach[Int](println)
val flow = source.to(sink)
flow.run()?