Keyboard

  • Generates messages that are handled by the operating system
  • Messages passed on to appropriate application
  • Applications do not have to handle all messages
Mouse
  • Generates messages for clicking and dragging handled by operating system
  • Messages passed on to appropriate application
  • All applications must handle double-clicking
System Message Queue
  • All messages initially are stored here before being processed for applications
  • Messages are translated into data that application can understand and use