A change in popes — through death or resignation — is a complicated process, with centuries-old rituals involving the transition in leadership for both the spiritual head of the global Catholic Church and the Vatican's head of state.
These are the need-to-know terms — some of them in Latin — to help make sense of news in the coming days:
Who is the Vatican camerlengo?
This is the ''chamberlain'' — the cardinal in charge of formally verifying the pope's death — and then sealing his room and study. Between then and the election of the new pope, the camerlengo administers the ''goods and temporal rights'' of the Holy See. The current one is the Irish-born American Cardinal Kevin Farrell.
Who is in the College of Cardinals?
There are 252 cardinals worldwide, and as a body, they are in charge of the Holy See's affairs in-between popes, albeit with limits. Of them, 135 are ''cardinal electors,'' who gather in the Vatican to choose the new pope. For centuries, they have chosen one of their own. The vast majority of the electors — 108 — were made cardinals by Pope Francis, according to Vatican statistics.
What is the conclave?
This is the closed-door meeting of the cardinal electors to choose the new pope in the Sistine Chapel. Its name, literally "with a key,'' was used in the 13th century to describe the process of locking up the cardinals until the election is completed. It must begin no more than 20 days after the death or resignation of a pope. The electors are sequestered from all outsiders for the duration; the last three popes were chosen within days.