Ash Wednesday is a Christian holiday that marks the beginning of Lent, 40 days of fasting, prayer, and repentance leading to Easter Sunday. On this day, many Christians attend church services and receive a mark of ashes on their foreheads, which symbolizes mortality and reminds them of their need for repentance and forgiveness. It is a solemn and reflective holiday that encourages spiritual introspection and renewal. In the United States, Ash Wednesday is observed by many Christian denominations and is considered an essential day in the liturgical calendar.