what is the purpose of command name and command argument for a control example button? when should we go for this?
CommandName:
When you have multiple
Buttoncontrols on a Web page, use theCommandNameproperty to specify or determine the command name associated with eachButtoncontrol. You can set theCommandNameproperty with any string that identifies the command to perform. You can then programmatically determine the command name of theButtoncontrol and perform the appropriate actions.
(My emphasis)
CommandArgument:
An optional parameter passed to the Command event along with the associated CommandName.
...which you retrieve from the event object (for instance, e) as e.CommandArgument.
So for instance, you might have four buttons with the CommandName "DoSomething" but four different CommandArguments telling your "DoSomething" code what to do, or what to do it to. You might also have other buttons with CommandName = "DoSomethingElse" that, well, do something else. :-)