What is the difference between VB6 and .net?
Visual Basic.net uses the Microsoft dotNET framework which makes it a more fully object oriented language. It's much tighter in a lot of areas in terms of what you're allowed to get away with. There's also no more 'Any', but since you haven't used VB6, that won't bother you, neither will the near eradication of 'Get' and 'Set'.

dotNET programs and assemblies can be registered for interop with COM (pre-dotNET assemblies) easily. Doing the reverse is very difficult.