Loop Back Test - Sticky?

It would help if someone please with these six questions?

  1. What do you sound?
  2. Where do I find the computer system protocol?
  3. What terminal do you mean Arduino IDE?
  4. How do I connect the terminal application to the serial port on my Arduino?
  5. I do not know why but the information that sends me not go back?
  6. What is the end application?