It is a candle that is lit from other candles and so unifying the flame, and in so doing, symbolises the unification of two families, two hearts, and/or two loves or lives i.e. making two into one.
The first candles may be lit by mothers or family members and handed to the couple who bring them together.
Another option is where all guests are also given a candle each, and after the first guest’s candle is lit, the flame is passed along until all are alight, and then the bride and groom together light their unity candle. This is to symbolise that it is the unity of not just family, but of friends who are supporting the couple in their marriage.
Once the Unity Candle is lit, the others may be extinguished because the flame of the Unity Candle is of course, the joining of all others.
The Unity Candle just needs to be prominent and so can be framed in a cage, on a pedestal, be the larger of other candles, or can be the higher, central candle on a candelabra.
If you have a candle from earlier in life such as from your Baptism or Naming Ceremony, you may wish to use that for the occasion or you may wish to have a new ornamental candle personalised with your names and the date, as a keepsake from your wedding.