Although Steu's response was accurate, I'm not too sure how 'clear' it was.
Visual Basic .NET: A programming language that compilies to the Microsoft .NET Framework.
Visual Studio .NET: An
Integrated
Development
Environment. Basically, a place to easily develop and compile your code. Visual Studio .NET supports writing in many languages; C++, C#, VB.NET, and PHP to name a few. There are different editions of VS.NET, just like there are different editions of Microsoft Office. Some only include VB.NET support, some only include C#, etc.
I do want to point out that there are alternitives to development in Visual Studio .NET. You could just download the Microsoft .NET SDK; which includes the full VB.NET and C# compilers, and just write your source in notepad (not very user friendly!). One of the best free/open-source alternitives to VS.NET is called
#Develop. #Develop doesn't have all the bells and whistles included in VS.NET, but if you're begining to write .NET code, I think most people would find it hard to shell out all that money for VS.NET when they don't even know the language.