Twitter than calls back and gives the application a token (a random number, essentially), which says this client has the right to respond on behalf of this user.
Many observers have suggested that adding at least three women to any type of team effort improves performance because a non-token number (three) counters group think, one of the greatest obstacles to creativity and innovation.
Think of the utility of a subway token in preference to cash, or (as in Monopoly), how much easier it is to move a game piece around a board than your physical self.