FileIO.FileSystem.CopyFile() vs System.IO.File.Copy()

Question

I have a couple of questions about the difference between this 2 classes and these specific methods, FileIO.FileSystem.CopyFile() and System.IO.File.Copy()

At the simplest level, they both do the same thing when overloaded with sourceFile, destinationFile and bool set to true to overwrite. EG

FileIO.FileSystem.CopyFile(source, destination, True) 
System.IO.File.Copy(source, destination, True)

My two questions are

1. What are the differences between the 2 with the overload shown because I can't find (or may be I missed the point) anything on the MSDN site.
2. How do you (the kind person answering) know the differences when it isn't in the MSDN documentation?

Answer 1

A quick look at Microsoft.VisualBasic.dll in reflector shows FileIO.FileSystem.Copy does just hand over to File.Copy after doing a couple of sanity checks (file, directory exists for example) and creating the destination directory if needed.