Sukkot is a Torah-commanded holiday celebrated for seven days and is one of the most joyful festivals on the Jewish calendar.
Beginning five days after Yom Kippur, Sukkot (say "sook-koht" or "sook-kuss") is named after the huts the Israelites lived in during their exodus from Egypt, which Jews today build to and dwell in to commemorate this time.
Sukkot is also a harvest holiday and the beginning of the season of prayers for rain.
"Festival of Ingathering" or "Harvest Festival", Sukkot is a little like Thanksgiving. As mentioned in the Book of Exodus, its meaning is agricultural in nature and marks the end of the harvest time and thus of the agricultural year in the Land of Israel. It is a festival for giving thanks for many things, like food and shelter. The holiday celebrates the farmer's yearly harvest, which takes place in the fall.
"Festival of Booths", is a more elaborate religious significance from the Book of Leviticus. It is commemorating the Exodus and the dependence of the People of Israel on the will of God.
The booths aspect of the festival may come from the shelters that were built in the fields by those involved in the harvesting process. Alternatively, it may come from the booths which pilgrims would stay in when they came in for the festivities at the cultic sanctuaries.
The holiday lasts seven days in the Land of Israel and eight in the diaspora. The first day (and second day in the diaspora) is a Shabbat-like holiday when work is forbidden. This is followed by intermediate days called Chol Hamoed, when certain work is permitted.
The festival is closed with another Shabbat-like holiday called Shemini Atzeret (one day in the Land of Israel, two days in the diaspora, where the second day is called Simchat Torah). Shemini Atzeret coincides with the eighth day of Sukkot outside the Land of Israel.
source: Wikipedia.org
As stated in Leviticus, it is also intended as a reminiscence of the type of fragile dwellings in which the Israelites dwelt during their 40 years of travel in the desert after the Exodus from slavery in Egypt. Throughout the holiday, meals are eaten inside the sukkah and many people sleep there as well.
On each day of the holiday it is mandatory to perform a waving ceremony with the Four Species (see below).
Inside the Land of Israel, the first day is celebrated as a full festival with special prayer services and holiday meals. Outside the Land of Israel, the first two days are celebrated as full festivals.
The seventh day of Sukkot is called Hoshana Rabbah ("Great Hoshana", referring to the tradition that worshippers in the synagogue walk around the perimeter of the sanctuary during morning services) and has a special observance of its own.
The intermediate days are known as Chol HaMoed ("festival weekdays") and according to Halakha, some types of work are forbidden during this time.
These are based on four plants mentioned in the Bible, and the rabbinic version includes the following: etrog (fruit of the citron tree), lulav (palm frond), hadas (leaves from the myrtle tree), and aravah (leaves from the willow tree).
This waving ceremony was performed at the Temple in the ancient world.
Food
Throughout the week of Sukkot, meals are eaten in the sukkah
There are no traditional Sukkot foods, except for kreplach (stuffed dumplings).
Meals can include fresh fruits and vegetables, or other harvest-related ingredients.