Processing + Arduino

I can’t understand this logic.

  1. Close Serial Monitor of Ard
  2. Start Prc. See the button
  3. Push the button
  4. See “2” on the Serila monitor of Prc
  5. Open Serial Monitor of Ard.
  6. Ard says: “Not Connected…”
  7. Stop Prc
  8. Close Serial Monitor Ard.
    9 Open Serial Monitor Ard
    10 Click Ctrl+Enter
    11 See “10” !!! What is this?