An explanation of some of the terms and practices related to the time between the death of Pope Francis April 21 and the election of his successor.

After the deaths or resignations of their predecessors, the last six popes have been elected within a fairly short period of time — between two and three weeks.

Cardinals already present in Rome and those who were able to get to the city after Pope Francis’ death April 21 held their first meeting at the Vatican April 22.

The funeral Mass of Pope Francis will be celebrated April 26 in St. Peter’s Square, the Vatican announced.

Over the course of his pontificate, Pope Francis held up two recurring images: the good shepherd who looks for the lost sheep and lays down his life to save them; and the good Samaritan, who did not ignore the wounded traveler, but helped him without asking for anything in return.

With his death April 21, Pope Francis marked yet another first in the history of the Catholic Church: he became the first pope to open the Holy Door of St. Peter’s Basilica without living to close it.

Pilgrims and tourists who had just one day earlier flocked to St. Peter’s Square awoke to the news that Pope Francis, who had greeted them there on Easter Sunday, had died. Pope Francis died at at 88, a few weeks after returning to his apartment at the Vatican following a five-week hospitalization for pneumonia.

Calling Pope Francis “a modern-day prophet,” Kerry Alys Robinson said the late pope “read the signs of the times and awakened us to meaningful change in our behavior — within the Church and within the world.”

In his brief final testament, Pope Francis asked to be buried at Rome’s Basilica of St. Mary Major and said he had offered his suffering for peace in the world.

Pope Francis, history’s first pope from the global south and a maverick who often delighted the world, died April 21 after fighting pulmonary disease for the last few months.