difference between .net framework and visual studio net?

The .NET framework is the layer which is installed on an Operating system (like windows) which holds everything you need to run a .NET application. It contains the libraries which provide functionality to, for example, open files, read xml, and so on.  

The .NET framework also includes the compilers for the various .NET languages. Like 'csc.exe' (C# compiler). This gives you the opportunity to write .NET applications, compile them and run them with only the .NET framework installed.

This is where visual studio comes in. VS.NET needs the .NET framework. Whenever you install VS, the install procedure will also install the .NET framework. VS.NET makes it much easier to create applications on the .NET framework by generating source code

You could say that VS.NET is a very fancy notepad for creating .NET applications in any way, shape or form.