Akka和Netty除了语言选择(Scala vs Java)之外还有什么不同?

I would like to understand the differences between Akka and Netty. I understand you can use both from Scala and Java. I am more interested in knowing where Netty is better (if anywhere) and where Akka is better (if anywhere). Where do they overlap, in other words, in what areas can I use Akka and not Netty and vice-versa.I would like to understand the differences betw