Pope Benedict XVI has greeted his cardinals for the last time as pontiff, beginning a quiet final day as leader of the world's 1.2 billion Catholics before flying off into retirement.

No major speech was planned during Thursday's farewell to his closest advisers. Cardinal Angelo Sodano, the dean of the cardinals, thanked Benedict for his service.

Around 5 p.m., Benedict will leave the palace for the last time as pontiff, head to the helicopter pad on the hill in the Vatican gardens and fly to the papal retreat at Castel Gandolfo. There, at 8 p.m. sharp, Benedict becomes the first pontiff in 600 years to resign. The doors of the palazzo will shut and the Swiss Guards in attendance will go off duty.

How does the Catholic Church even get a new pope? Well, the current one either dies or resigns. Then the church holds a papal conclave and cardinals under the age of 80 vote on who they want to lead them. This time around, 115 cardinals will be voting.

The conclave begins with the cardinals in their red cassocks filing into the Vatican's Sistine Chapel, chanting the ``Litany of Saints.'' Then they place their hand on the Gospel and promise to observe absolute secrecy during and after the conclave.
They also vow to vote independently, a good way to guard against external interference. During the conclave, the cardinals live in a Vatican hotel andhave no contact with the outside world: no phones, no newspapers, no tweeting.

On Day 1, only one round of balloting is held; after that, the cardinals cast two votes in the morning and two in the afternoon until one man has a two-thirds majority.

The outside world only knows what is going on by seeing smoke from the Sistine Chapel each time the ballots are burned. Black smoke means no decision, white smoke means a pope has been chosen. Soon afterward, the thousands of faithful in St. Peter's Square will hear two Latin words announced from the balcony: ``Habemus Papam! (We have a pope!)''

(The Associated Press)