A message is an announcement that an event has occurred, for example, when the user taps a button or adds a new card to the stack.

When an event occurs, NovoCard creates a message and decides where to send it by determining what object the user acted on. This object becomes the target for the message (a button, field, picture, portal, shape, card, background, or stack).

When NovoCard knows the message name (based on the event) and the destination of the message (the target object), it sends the message to the object.