Comments are used to leave yourself notes or to mark a piece of code so that it doesn't get executed. In VBScript the comment system is extremely simple because there is only one kind of comment.

VBScript only has support for single line comments, so commenting out large blocks of code or leaving yourself long notes can be quite a bit of work. The apostrophe is the special character VBScript uses as its comment initiator.

Example:

Dim myMessage
'myMessage = "this is first comments
myMessage = "This is message"

'this is another comment
document.write(myMessage)

This is message

Commenting out segments of code is often quite beneficial when you are trying to debug your VBScript code. Leaving yourself notes in your VBScript is also a good programming practice, as it will remind you of the code's purpose months or even years later when you might be reviewing the code for the first time in a long time.