We use the Latin phrase "Apostolica Sedes Vacans" when the Papacy is vacant because of the death or resignation of a Pope. During this time, the Catholic Church is administered by the College of Cardinals although with a limited authority –they cannot make significant decisions. As mentioned on Aleteia, this temporary pause shows us how the unity of the Church is entrusted to one man's office not as a symbol of human power, but as living witness to Christ's care for His people.
As Catholics, we are called to pray for the cardinals, future Pope and our Holy Church.