The reign of Pope Francis is over, and as the Catholic Church mourns his death, it is also looking to the future. Soon after Saturday's funeral, a papal conclave must be held to choose his successor,

A papal conclave, the election of a new pope, tends to begin 15-20 days after a papal vacancy. Black or white smoke indicates each day's decision.

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.