Why would one want to learn and/or practice using servers with Java SE, over using the EE approach?

I think I have a basic understanding of why, but I can't articulate the reasoning. If I understand correctly, doesn't SE use sockets, streams etc, while EE (servlets开发者_高级运维 etc) basically "does all that work for you", so to speak? In other words, aren't they more or less doing the same thing, but it just helps to understand the underlying process via SE servers..?

It's always useful to understand what's going on at a lower level:

1. you may want to use some approach not catered for by standard EE application servers (e.g. you may want to make use of something like Apache Mina, or code a trivial client/server that doesn't need the EE overhead)
2. You may need to debug or otherwise troubleshoot your application server. Under the covers it'll being using sockets etc. and simply wrapping those in some 'friendly' APIs and frameworks.

If you have that fundamental understanding you can understand what's going on, the limitations of chosen solutions, how to improve on them, and translate the concepts into different platforms and languages.