The Holy See-Pope's catechesis: the meaning of Lent:

Dear Brothers and Sisters, Today the Church celebrates Ash Wednesday, the beginning of her Lenten journey towards Easter. The entire Christian community is invited to live this period of forty days as a pilgrimage of repentance, conversion and renewal. In the Bible, the number forty is rich in symbolism. It recalls Israel’s journey in the desert, a time of expectation, purification and closeness to the Lord, but also a time of temptation and testing. It also evokes Jesus’ own sojourn in the desert at the beginning of his public ministry, a time of profound closeness to the Father in prayer, but also of confrontation with the mystery of evil. (News.Va:here)