How to get started with Akka Streams? : <p>The Akka Streams library already comes with quite a <a href="http://doc.akka.io/docs/akka/2.4.2-RC1/scala/stream/index.html">wealth of documentation</a>. However, the main problem for me is that it provides too much material - I feel quite overwhelmed by the number of concepts that I have to learn. Lots of examples shown there feel very heavyweight and can't easily be translated to real world use cases and are therefore quite esoteric. I think it gives way too much details without explaining how to build all the building blocks together and how exactly it helps to solve specific problems.</p>

<p>There are sources, sinks, flows, graph stages, partial graphs, materialization, a graph DSL and a lot more and I just don't know where to start. The <a href="http://doc.akka.io/docs/akka/2.4.2-RC1/scala/stream/stream-quickstart.html#stream-quickstart-scala">quick start guide</a> is meant to be a starting place but I don't understand it. It just throws in the concepts mentioned above without explaining them. Furthermore the code examples can't be executed - there are missing parts which makes it more or less impossible for me to follow the text.</p>

<p>Can anyone explain the concepts sources, sinks, flows, graph stages, partial graphs, materialization and maybe some other things that I missed in simple words and with easy examples that don't explain every single detail (and which are probably not needed anyway at the beginning)?</p>
