Ash Wednesday marks the first day of Lent in the Western Christian liturgical year. Lent is a season of spiritual discipline, cleansing, and fasting which occurs in the forty days (excluding Sundays which are not considered part of Lent) before Easter.
On Ash Wednesday, a priest or pastor marks a cross on the forehead of parishoners. The ashes are obtained from the burned palms used in the previous year's Palm Sunday celebration. This ritual is blessed with a passage from Genesis 3:19: "for dust thou art, and unto dust shalt thou return." The ashes symbolize repentance and purification.