Turning off the Airbus A320 involves a series of steps to safely shut down the aircraft. Here’s a basic rundown of the shutdown procedure:

1. After Landing:
   
   

   • Complete all landing and taxiing procedures as usual, including parking the aircraft at the gate or parking position.

2. APU (Auxiliary Power Unit) - Start Shutdown:
   
   

   • Ensure that the aircraft is in "Parked" mode.

   • Turn off the autopilot and autothrust (if not already disengaged).

   • Turn off the landing lights, nose light, and strobes.

   • Set the parking brake.

3. Engines Shutdown:
   
   

   • Thrust Levers: Move both the thrust levers to idle.

   • Engine Master Switches: Set both engine master switches (for engine 1 and engine 2) to OFF.

4. Electrical Systems:
   
   

   • Ensure the battery master switch is in the "OFF" position.

   • If necessary, ensure that external power is available (if using ground power), and connect it.

5. Air Conditioning / Bleed Systems:
   
   

   • Switch off air conditioning and bleed air systems to ensure the aircraft is no longer using engine or APU bleed air.

6. Flight Deck Instruments and Systems:
   
   

   • Turn off any other non-essential flight deck systems (i.e., avionics, displays, lights).

7. Final Steps:
   
   

   • Complete the aircraft shut down checklist to ensure all systems are properly shut down and secured.

These steps are a simplified guide, and it’s important to refer to the A320's official checklist and operating manual for specific aircraft configurations and safety protocols.