Sukkot (Hebrew: סוכות or סֻכּוֹת sukkōt or sukkos, Feast of Booths, Feast of Tabernacles) is a biblical holiday celebrated on the 15th day of the month of Tishrei (variously from late September to late October). It is one of the three biblically mandated festivals Shalosh regalim on which Hebrews were commanded to make a pilgrimage to the Temple in Jerusalem. It follows the solemn holiday of Yom Kippur, or the Day of Atonement.
The holiday lasts seven days (eight in the diaspora). The first day (and second in the diaspora) is a sabbath-like yom tov when work is forbidden, followed by the intermediate Chol Hamoed and Shemini Atzeret. The Hebrew word sukkōt is the plural of sukkah, "booth or tabernacle", which is a walled structure covered with skhakh (plant material such as leafy tree overgrowth or palm leaves).
The sukkah is 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 some people sleep there as well. On each day of the holiday, members of the household recite a blessing over the lulav and etrog (Four species).
According to the prophet Zechariah, in the messianic era Sukkot will become a universal festival and all nations will make pilgrimages annually to Jerusalem to celebrate the feast there.
Read more about Sukkot: History, Laws and Customs, Building A Sukkah, Special Prayers, Chol HaMoed, Hakhel, Simchat Beit HaShoevah, Hoshana Rabbah, Shemini Atzeret and Simchat Torah