The wreath comes with 4 candles for Catholics and 6 candles for Orthodox (one for each Sunday of Advent). The latter are lit in Christian homes, one at a time, every Saturday evening preceding the 4 or Sundays of Advent, to mark the stages of the period leading up to Christmas.

History

The hanging Advent wreath without candles is an ancient symbol in the Church. In a drawing completed around 983 and preserved in the Trier State Library, an Advent wreath is evident above Pope St. Gregory I († 604) dictating either a theological commentary or the Advent introit, Ad te levavi.

The origin of Advent candles goes back to the initiative of a German pastor who decided to light a candle on a wheel every day, to mark the 24 days leading up to Christmas. The Advent wreath with candles was invented by Pastor Johann Heinrich Wichern (1808-1881), an educator and theologian from Hamburg. Every morning, a small candle was lit, and every Sunday in Advent a large candle. The Advent custom retained only the larger candles.
Advent wreaths with candles were later adopted in Lutheran and Catholic circles throughout Germany.
Christmas wreaths, hung on doors, are Anglo-Saxon and aligned with the old protective custom of decorating the entrance to houses with a bunch of holly.
In France, the wreath made a timid appearance in the first third of the 20th century. Long associated with funeral rites, it only became widespread in the second half of the twentieth century.
The symbol
The Christian community has often acclimatized customs inherited from cosmic tradition. It seems that the word "pagan" doesn't necessarily have a pejorative meaning: it's a form of the word "peasant", and the habits associated with it are those of rural life, punctuated by the seasons, the movement of the stars, the impressive manifestation of the impersonal divine in the great signs that man contemplates with his own eyes, reading creation with an open book.
However, the evangelization of the cosmic tradition has given new meaning to inherited symbols. The very principle of liturgy is the use, with the most appropriate words, of symbolic language, which touches the conscience more deeply than conceptual language does.
Sanctifying time
The circle is often a symbol of time. In this sense, it is not really a biblical symbol, since, for Sacred Scripture, time is not cyclical, but linear, oriented towards an end, the end of history, the ultimate blessing given by God for the great fulfillment. But the circle is to be found in many of our rites and gestures: circular processions, wedding rings, bridal crowns... It is then a sign of eternity.
What is circular relates to the celestial. The Advent wreath can thus be deciphered as the symbol of a particularly consecrated period of time, inscribed in the heavens, that which prepares the bodily manifestation of the creative Word, carried in the Virgin's womb since March 25.
Traditionally, the crown is a sign of victory, for example in athletic games or in the example of martyrs crowned because their faith triumphed over trials. It symbolizes the sovereign advent of divine Light, of Christ, the Light of the nations.
The wreath is a circle that reminds us that the festive season comes around every year. It also symbolizes that Jesus is coming back, and that Advent is not just a time of anticipation before Christmas, but also of Christ's Return.
When all six candles are lit in the run-up to Christmas, it will be clear that the light has won, even though darkness has overtaken the universe!

In practice

The Advent wreath is often made of evergreen branches and foliage of pine, yew and laurel, to signify life. It is tied with a red ribbon and decorated with pine cones.
At home, it hangs from the ceiling or is placed on the dining table, or near the icons where we pray.
Six candles are fixed to it, designating the six weeks of the Christmas fast in some Western countries, notably Gaul (hence the name Saint Martin's Lent for a period running from November 11 to December 25); Eastern Churches have six weeks since the feast of Saint Philip, on November 14.
These beautiful wax candles are lit week by week, in the evening, recalling the ancestral expectation of light in a world of darkness (cf. Luke 11:79), the prophets announcing the Messiah. They symbolize the approaching light of Christmas, bringing hope and peace.
Firstly, in the (non-Orthodox) West, the first Sunday of Advent is considered the beginning of the liturgical year. (In the East, the liturgical year does not begin with Advent but on September 1, which bears the traditional title of "Crown of the Year." Its historical relationship with the Jewish feast of Rosh Hashana is obvious).

(machine translation)

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