I am new to Java and am a little bit confused about how NetBeans manages directory structure. I understand there are structure with main project name directory, then src, build, dist, etc.
But what I don't understand is why NetBeans creates two-level directory in my case below:

What's the difference between directories project and myapp?
Folder project contains myapp only and myapp contains src, dist, build, etc. Another picture:

What is directories project and myapp for? What's the difference between them?