A consistory is a formal meeting of the College of Cardinals.
The pope can convene them for several different reasons.
One of the most common reasons for a consistory is to create new cardinals.
The ceremony in which the pope makes cardinals is an ordinary public consistory.
In addition to the red biretta, at the ceremony, Pope Francis placed a ring on the hand of each new cardinal while saying: “Receive this ring from the hand of Peter and know that, with the love of the Prince of the Apostles, your love for the Church is strengthened.”
The pope will also assign each new cardinal a church in the Diocese of Rome, called a “titular church.” This further links the cardinal to Rome and to the pope, who is the Bishop of Rome.
The other members of the College of Cardinals, clergy, Catholics, and members of the public may all attend a consistory to create cardinals.
Another consistory the pope may convene is an ordinary consistory to vote on the causes of new saints, the last step before a formal canonization can take place.
There are also extraordinary consistories, which every cardinal is expected to take part in, barring a serious reason.