I'm all confused. How many candles do I need to light before Yom Kippur and why am I lighting them?
On Yom Kippur we light (1) candles in honor of the holiday, (2) candles in honor of our deceased parents, (3) candles in the synagogue, and (4) candles to use in havdalah. Here is a little information about each of these candles:
1. Before Shabbat and holidays, women and girls light candles in honor of the day. They light candles before Yom Kippur begins, just like they do on all other holidays. Click here to see the blessings recited before lighting these candles.
In a household where there are no women, a man should light candles. On Shabbat or other holidays, a man who lives in a womanless household and plans to eat out that evening can fulfill his obligation to light Shabbat candles if he contributes some money toward the candles lit at the home where he will eat his festive meal. As there is no holiday meal on Yom Kippur, men should be aware that they must light candles themselves.
Unlike the other candles discussed in this article, these candles do not need to last for the entire twenty-four hours of Yom Kippur.
2. Since it is impossible to honor Yom Kippur with food and drink as we do for other holidays, we honor it by lighting extra candles, as Isaiah writes, "With lights, honor G‑d." For this reason, it is customary to light many candles in the synagogue. In earlier times both young and old would have a candle lit for them. Today only married men light candles in the synagogue.
This candle should be big enough to burn the entire Yom Kippur and is called in Yiddish dos lebidikeh licht (the living light) or the dos gezunteh licht (the healthy light).
3. It is customary to light a candle on every holiday on which yizkor is recited, as a memorial for one's departed parents. A candle is an appropriate memorial for the deceased; a flame symbolizes the human soul, as King Solomon writes in Proverbs, "A flame of G‑d is the soul of man." Perhaps the earliest record of a candle memorializing a dead person is in the Talmud: Rabbi Yehudah, on his deathbed, requests of his sons that the candle which burned in his place during his lifetime should continue to burn after his passing.
This candle, known in Hebrew as a ner neshama (soul light), should burn the entire Yom Kippur and is lit at home.
4. During the post-Shabbat havdalah, we say, "Blessed are you, L‑rd our G‑d, King of the universe, who creates the lights of fire" while holding a multi-wicked candle. This blessing is appropriate on Saturday night, as Adam created fire for the first time on Saturday night. On holidays other than Yom Kippur, we don't recite this blessing during havdalah, because fire is not relevant to the end of the holiday. After Yom Kippur we do say this blessing, as cooking and adjusting the size a flame are forbidden on Yom Kippur (unlike the other holidays).
The idea behind the post-Yom Kippur havdalah candle is different than that of the post-Shabbat candle. The point of the post-Shabbat candle is to commemorate how fire was created from new. Therefore we can use fire which was created on Saturday night. The point of the post-Yom Kippur candle is that until now fire was forbidden, and now it is permitted. We therefore use a flame that "observed" Yom Kippur, i.e. it was lit before Yom Kippur and was not adjusted on Yom Kippur. In order to have such a candle after Yom Kippur ends, we light a 24-hour candle before Yom Kippur.
The candle which was lit in honor of one's deceased parents can also be used for havdalah.
In earlier generations, one candle would be lit to satisfy the last three of the above-mentioned reasons, as is seen in Kol Bo, an authoritative book (although of uncertain authorship) which seems to have been written around 700 years ago. Here's a loose translation of what Kol Bo says on this topic:
It is customary for everyone to light a candle or torch on Yom Kippur to atone for his father and mother... The Holy One Blessed be He says, "Light before me a candle so that I will guard your souls, which are called 'candles'." Another reason [for this custom]: we read from books all day and all night constantly, and we read prayers and supplications which we do not know by heart, and without this light, we would not be able to see and read at night. Another reason: [the candle is] for the honor of G‑d and the honor of the synagogue, as it says, "With lights, honor G‑d." And also, to be able to recite havdalah over that candle at the end of Yom Kippur.
Wishing you a light fast, an enlightening Yom Kippur, and a shining new year!