Common Rosh Hashana and Yom Kippur are called both "head". Rosh Hashanah, as its name implies is the head of the year (Rosh in Hebrew is head), but Yom Kippur is also known as New Year's in the...
Eve of Yom Kippur is a special day. Besides being busy preparing for the fasting, is considered as 'Yom Tov' and do a holiday meal.
Here's the special law relating to this day.