An example of an Advent wreath - using blue and red candles
Advent is the season before Christmas during which Christians celebrate the birth of Jesus.
In Western Christendom, four Sundays are included, but in the East the season is longer and begins in the middle of November.
However, Advent always finishes on Christmas Eve. If that falls on a Sunday, it is considered to be the fourth Sunday of Advent.
The name Advent comes from the Latin word 'adventus' meaning arrival.
Using an advent wreath and four candles - one to symbolise each of the Sundays in Advent, Christians celebrate this time of year by praying together and enjoying the time as a family.
Advent calendars were created to hold the younger members of the families' attention during the time, helping them to count down the days until Christmas Day.
The calendars have since gone on to be used by non-Christians, and sold with chocolates inside for each day.
An Advent candle that would be used at home, to burn each day
Four candles are used within the church environment during advent, but lots of Christians will burn an Advent candle at home too.
These candles will come with markings down them, and will be burnt down each day to the next marker, so the candle will be fully burnt away come Christmas Day.
In Catholic churches , the most popular colours for the Advent candles are purple and rose.
Rose is the colour for the Third Sunday of Advent, known as Gaudete Sunday from the Latin word for 'rejoice', and the rose colour is a mix of the purple, and white - representing that Christmas is coming.
In Protestant churches, it is more usual to use four red candles, which is more in keeping with traditional Christmas decoration colour.
Other variations of the Advent wreath add a white candle in the centre to symbolize Christmas, sometimes known as the 'Christ candle'. It can be lit on Christmas Eve or Christmas Day.