Port connection Architecture and Device browser proxy settings

I have following queries on ports used in appium

  1. http://127.0.0.1:4723 : Does Appium server listens and sends data on the same port 4723 to both device and Selenium ??
  2. –bootstrap-port 4724 : what is the role of port ?
  3. How to change Mobile Chrome browser proxy settings using desired capabilities

Please provide flow diagram