1,002. Beginning Hilchos Yom Tov
Shvisas Asor 3:10
In some communities there is a practice to light a candle for Yom Kippur so that one will refrain from marital relations. In other communities, the practice is not to light a candle out of concern that one will see his wife and feel attracted, which would tempt one to have marital relations. When Yom Kippur falls on Shabbos, all communities light a candle, as one is obligated to do for Shabbos.
Shvisas Yom Tov 1:1
There are six days on which the Torah prohibited acts of creative labor: the first and seventh days of Pesach, the first and eighth days of Succos, the holiday of Shavuos and the first day of the seventh month (i.e., Rosh Hashana). These days are called “yom tov.” The rest on these days is identical. One may only perform acts of labor that are necessary for the preparation of food, as per Exodus 12:16, “Except that by which every person may eat….”