In the Catholic Church in the west at least today, Advent is emphasized as a time of waiting, preparation for the coming of Jesus Christ--in the future and in history. There are some elements of penitence: vestments are purple; we do not sing the Gloria at Sunday Masses; we hear often about the counter-cultural nature of Advent as we wait to celebrate Christmas and then celebrate Christmas for a season and not just a day. That's the position of Advent overall.
Before the English Reformation, Advent was a season of penitence and fasting--except I suppose where the Boy Bishop handed out treats and declared holidays from December 6 to December 29!!--preparing for the feast of Christmas with its joyous celebration. There were no marriages during the season of Advent (or of Lent) and the Ember Days (Mondays, Wednesdays, and Fridays after December 13, the feast of St. Lucy) of the Advent season were Fast Days. As Christmas was one of the great feasts of the year when the laity would receive Holy Communion, parishioners prepared by receiving the Sacrament of Penance, examining their consciences, confessing their sins, and fulfilling the penance given by the priest.
As Eamon Duffy comments in both The Stripping of the Altars and The Voices of Morebath, the seasons and feasts of the Church year were integrated parts of the social and personal life of Catholic Christians in England before the English Reformations of Henry VIII, Edward VI, and Elizabeth I. They provided order and remembrance; most events would be dated by a religious date: a child was born two days after Michaelmas; a couple were married five days after Christmas; a father died on the eve of Candlemas. (Wouldn't help much to use the movable feasts of Easter and Pentecost!) The feasts and seasons provided a pattern of work and rest, fasting and feasting, life and death. That pattern is certainly something lost after the Reformation Parliament.