What is the difference between Dim and Private in VB.NET?
Dim declares and allocates space for a variable. Private is used to specify an access level that means only the declaring class can see or use the declared member.
I believe your question comes from the fact that you sometimes see things like:
Class MyDemoClass
Dim mVar1 As Integer
Private mVar2 As Integer
End Class
In the above example mVar1 and mVar2 declarations are logically equivalent - they both boil down to Private Dim mVar as Integer.
MSDN explains this here:
The Dim keyword is optional and usually omitted if you specify any of the following modifiers: Public, Protected, Friend, Protected Friend, Private, Shared, Shadows, Static, ReadOnly, or WithEvents.