On the four Sundays before Christmas western Christians around the world observe a season of increased reflection, prayer, fasting, and charity in preparation for the Christmas season that begins (not ends) with Christmas day. It is the most recent major Christian liturgical tradition that developed in the 4th and 5th centuries and originally started as a season of fasting and repentance, like that of Lent, that began after the feast of Saint Martin on November 11. The Orthodox church still observes it primarily as a 40 day fast beginning on November 15.
Advent today the western tradition no longer carries the same emphasis on repentance and fasting that the original tradition did, more emphasis is placed on prayer, reflection, and charity as the means by which the Christian prepares his heart to receive the advent of Christ at Christmas, as well as preparation to receive him at the advent of the second coming.
Celebrating Advent in the Catholic/Protestant tradition
Celebrating Advent in the Orthodox tradition (coming soon)
Discovering the Saints 