Lent is the period of forty days leading up to Easter.
The day before it starts is called Shrove Tuesday.
Ash Wednesday is the first day of Lent and in some churches people have ashes placed on their heads as a sign of repentance. These ashes are sometimes from the previous year's palm crosses (see Palm Sunday) which have been burned.
Lent is the season marking the time Jesus spent in the desert. Traditionally people ‘give something up for lent’ such as eating chocolate or sweets.