An Apostolic Letter is a formal document issued by the Pope, often addressing specific issues or providing guidance to the Catholic Church. These letters can cover a wide range of topics, including doctrine, morality, or social issues, and are intended to communicate the Pope's teachings and directives to the faithful. Unlike encyclicals, which are more comprehensive and typically address broader themes, Apostolic Letters are usually shorter and more focused. They may be directed to particular groups, such as bishops or laypeople, and can also serve to announce important events or initiatives within the Catholic Church.