Online and offline.
Yes.
no , but call of duty modern warfare reflex (cod4) has
Yes
yes
I believe Call of Duty 1, 2 and 3
if you mean offline then no sorry well if it was i would be playing it but i am sorry :(
number one
yes it is for single player offline and multiplayer online if by classic you mean Call of Duty 3 see related link
You can't. But I think you can with Modern Warfare 2's new multiplayer system.
Yes, Call of Duty: Black Ops will have online multiplayer just like many other Call of Duty video games.
Depends, which Call of Duty are you talking about.