The name \"Yom Kippur\" means \"Day of Atonement,\" and that pretty much explains what the holiday
is. It is a day set aside to \"afflict the soul,\" to atone for the sins of the past year.

On Yom Kippur, the judgment
entered in these books is sealed. This day is, essentially, your last appeal, your last chance to change
the judgment, to demonstrate your repentance and make amends.
The ten days starting with Rosh Hashanah and ending with Yom Kippur are commonly known as the
Days of Awe (Yamim Noraim) or the Days of Repentance. This is a time for serious introspection, a
time to consider the sins of the previous year and repent before Yom Kippur.

One of the ongoing themes of the Days of Awe is the concept that G-d has \"books\" that he writes
our names in, writing down who will live and who will die, who will have a good life and who will
have a bad life, for the next year. These books are written in on Rosh Hashanah, but our actions
during the Days of Awe can alter G-d\'s decree. The actions that change the decree are \"teshuvah,
tefilah and tzedakah,\" repentance, prayer, good deeds (usually, charity). These \"books\" are sealed
on Yom Kippur.

Another custom observed during this time is kapparot. This is rarely practiced today, and is
observed in its true form only by Chasidic and occasionally Orthodox Jews. Basically, you purchase
a live fowl, and on the morning before Yom Kippur you waive it over your head reciting a prayer
asking that the fowl be considered atonement for sins. The fowl is then slaughtered and given to the
poor.

It is customary to wear white on the holiday, which symbolizes purity and calls to mind the promise
that our sins shall be made as white as snow (Is. 1:18). Some people wear a kittel, the white robe in
which the dead are buried (under the altar)

Note that all sins are confessed in the plural (we
have done this, we have done that), emphasizing communal responsibility for sins.

There are two basic parts of this confession: Ashamnu, a shorter, more general list (we have been
treasonable, we have been aggressive, we have been slanderous...), and Al Chet, a longer and more
specific list (for the sin we sinned before you forcibly or willingly, and for the sin we sinned before
you by acting callously...) Frequent petitions for forgiveness are interspersed in these prayers.
There\'s also a catch-all confession: \"Forgive us the breach of positive commands and negative
commands, whether or not they involve an act, whether or not they are known to us.\"
The vast majority of the sins
enumerated involve mistreatment of other people, most of them by speech (offensive speech,
scoffing, slander, talebearing, and swearing falsely, to name a few). These all come into the category
of sin known as \"lashon ha-ra\" (lit: the evil tongue), which is considered a very serious sin in Judaism.

The concluding service of Yom Kippur, known as Ne\'ilah, is one unique to the day. It usually runs
about 1 hour long. The ark (a cabinet where the scrolls of the Torah are kept) is kept open
throughout this service, thus you must stand throughout the service. There is a tone of desperation in
the prayers of this service. The service is sometimes referred to as the closing of the gates; think of it
as the \"last chance\" to get in a good word before the holiday ends. The service ends with a very long
blast of the shofar.

 http://www.jewfaq.org/holiday4.htm

The Festival of Sukkot begins on Tishri 15, the fifth day after Yom Kippur. It is quite a drastic
transition, from one of the most solemn holidays in our year to one of the most joyous.
This festival is sometimes referred to as Zeman Simkhateinu, the Season of our Rejoicing. Sukkot
lasts for seven days. Sukkot is also a harvest festival, and is sometimes referred to as
Chag Ha-Asif, the Festival of Ingathering.