VB.NET supports two ways to implement comments in code. First, the old Visual Basic way using a REM keyword followed by comment and second, the new VB.NET way, using a single quote. Visual Studio 2010 also support automated comments. If you use three single quotes at top of a function or method and hit ENTER, you will see pre-formatted comments help is generated as you can see from Listing 2. Listing 2 shows both REM and single quote approach for comments.
''' <summary> ''' This is automated generated standard comment in Visual Studio
''' Use thre singe quotes and hit ENTER, it will generate summary and
''' other comments for the entire function
''' </summary>
''' <param name="NumberOne"></param>
''' <param name="NumberTwo"></param>
''' <returns></returns>
''' <remarks></remarks>
Function LineContinuationSnippet(ByVal NumberOne As Integer, _
ByVal NumberTwo As Integer) _
As Integer
' Check if NumberOne > NumberTwo
If (NumberOne > NumberTwo Or _
NumberOne = NumberTwo) Then ' If True, then go here
REM Return NumberOne
Return NumberOne
Else
REM Return NumberTwo
Return NumberTwo ' REM can be used here too
End If
End Function
Listing 2
Read this article to learn more about Comments in VB.NET