Advent is a season of hope. In the Spirit of Christ, the definitive communion with God the Father is already present in history, even if in a mysterious and invisible way. Hope for the believer is not merely waiting for something to happen; it is a commitment, here and now, to build the Kingdom of God. Hope, {on the one hand encourages the Christian not to lose sight of the final goal, which gives meaning and value to life, and on the other, offers solid and profound reasons for a daily commitment to transform reality in order to make it correspond to God’s plan}. Our reason for hope is intimately tied to our waiting, which is characteristic of the liturgy of the Third Sunday: "Rejoice in the Lord always; again I say, rejoice! The Lord is near" (Phil 4,4-5)(3). It is Christ himself who is the subject of Christian hope, the mystery hidden in time and now revealed: "Christ among you, your hope of glory" (Col 1, 27).
source: http://www.vatican.va/jubilee_2000/magazine/documents/ju_mag_01111997_p-66_en.html
The Advent season is a time of preparation that directs our hearts and minds to Christ’s second coming at the end of time and also to the anniversary of the Lord’s birth on Christmas. The final days of Advent, from December 17 to December 24, focus particularly on our preparation for the celebrations of the Nativity of our Lord (Christmas).
Advent devotions including the Advent wreath, remind us of the meaning of the season. Our Advent calendar above can help you fully enter in to the season with daily activity and prayer suggestions to prepare you spiritually for the birth of Jesus Christ. More Advent resources are listed below.
source: http://www.usccb.org/prayer-and-worship/liturgical-year/advent/