When a pope dies or resigns, the governance of the Catholic Church passes to the College of Cardinals. Cardinals are bishops and Vatican officials from all over the world, personally chosen by the pope, recognizable by their distinctive red vestments.
Following a vacancy in the papacy, the cardinals hold a series of meetings at the Vatican called general congregations. They discuss the needs and the challenges facing the Catholic Church globally. They will also prepare for the upcoming papal election, called a conclave. Decisions that only the pope can make, such as appointing a bishop or convening the Synod of Bishops, must wait till after the election. In the past, they made arrangements for the funeral and burial of the deceased pope.
Read more: How is a new Pope Chosen - USCCB