As what i see, most .NET source code looks the same regardless of the specific language it carries. I see that way because all of them share same framework .NET which has functions, libraries, objects, etc...Am i correct?

so why they call them in different names C++.NET, VB.NET, C#.NET ....

If thats the case, If thats the case, why should we concern with which language to go such as VB.NET, C#.NET or C++.NET? Why isn't called .NET programming language only? Because anything under .NET shares same syntax, structure of coding.