Simply put, a conclave is the assembly of cardinals that elects a pope. The word itself comes from the Latin "com" and "clavis," meaning "together" and "key," respectively – highlighting the absolute, behind-closed-doors secrecy with which the cardinals conduct their discussions and balloting.

At the end of a pope's reign, a secret vote takes place at the Sistine Chapel in Vatican City, Rome. Here is the election process for a new pope.

As Vatican officials prepare to lay Pope Francis to rest Saturday at St. Peter's Basilica, members of the College of Cardinals are likely looking ahead to the possibly lengthy process to choose his successor.