Advent (from the Latin adventus meaning "coming" or "arrival") is the season before Christmas in some Christian traditions. It includes four Sundays starting with the one nearest Saint Andrew's Day (November 30th) and marks the beginning of the church year.
According to Advent's theme of Christ's appearance, the readings include the messianic prophecies of Isaiah and the portions of the Gospels concerning John the Baptist. In the Roman Catholic, Anglican, Lutheran, and Methodist traditions, purple is the color normally used for Advent decorations and priestly vestments. Advent hymns often include "O Come, O Come Emmanuel" and "Come Thou Long Expected Jesus."
During Advent, four candles within a wreath may be set near the church altar. In some churches, four purple candles are used. In others, three of the candles are purple and one is pink.
On the first Sunday of Advent a purple candle is lit; on the second Sunday two of the purple candles are lit, on the third Sunday two purple candles and the pink (rose) candle are lit; on the fourth Sunday of Advent all four candles are lit. The rose-colored candle marks the passage beyond the halfway point of Advent. Its color suggests a moderation of the soberness of the Advent season in view of the nearness of Christmas, a day of celebration. The day of the lighting of the third candle is called Gaudete Sunday. On Christmas Day, a white "Christ Candle" is often placed in the center of the Advent Wreath and lit.
An Advent Wreath or Advent Calendar may also be kept in the home to mark the timing of the season before Christmas. Traditionally, family prayers are recited on the occasion of the lighting of each candle in the home.
The New American Desk Encyclopedia, Penguin Group, 1989