[HELP] Arduino Wifi Controller [URGENT]

Hi everyone, I am facing problems with the use of Arduino.
I have just a little knowledge about Arduino.
I am now handling a project which could control the device through the internet.
And now my problems are :

  1. how does Arduino connect with my device (Vacuum Cleaner) in order to let it control through the internet? Example codes?
  2. can Arduino contact with XBee (wireless control) ? both using the same language?
  3. which Arduino should I choose for this project? Arduino Ethernet Shield or Arduino Wifi Shield?

Thousands of thanks for those who willing to help me to solve it.
I need some guidance now :~

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