In the Catholic Church, "Blessed" is a title given to a deceased person who has been beatified and is thus worthy of public veneration in a particular region or religious group. This is the third step in the four-stage process of canonization, the process by which a person is declared a saint.
To be declared "Blessed," a miracle must typically be attributed to the person's intercession after their death and subsequently validated by the Church. The miracle is usually a healing that is medically inexplicable, instantaneous, lasting, and directly related to the intercession of the Venerable servant of God. The Pope then declares that the person lived a life of heroic virtue and is now in heaven and can intercede for us, which is the essence of beatification.
The declaration of "Blessed" allows for public veneration of the person, but this veneration is usually limited to specific places, such as a particular diocese or country, or among specific groups of people. In order to be canonized and declared a saint, which allows for universal veneration, an additional miracle is typically required, attributed to the person's intercession after the beatification.