Advent is a season observed in most Christian denominations as a time of waiting and preparation for both the celebration of Jesus's birth at Christmas and Jesus's return at the Second Coming. It begins on the fourth Sunday before Christmas, often referred to as Advent Sunday. Advent is the beginning of the liturgical year in Western Christianity. The name comes from Latin adventus ('coming; arrival'), translating the Greek parousia from the New Testament, originally referring to the Second Coming.

The season of Advent in the Christian calendar anticipates the "coming of Christ" from three different perspectives: the physical nativity in Bethlehem, the reception of Christ in the heart of the believer, and the eschatological Second Coming.

-Wikipedia