While the festival of Sukkot is a joyous occasion, and is referred to in Hebrew as Yom Simchateinu (the day of our rejoicing) or Z'man Simchateinu, (the season of our rejoicing), the sukkah itself symbolizes the frailty and transience of life. It also reminds its dwellers that true security comes from faith in God, rather than from money or possessions.
Since Sukkot celebrates the harvest in the land of Israel, another custom on Sukkot is involves waving the lulav and etrog. Together the lulav and etrog represent the Four Species.
The etrog is a kind of citron, while the lulav is a composed of three myrtle twigs (hadassim), two willow twigs (aravot) and a palm frond (lulav). Because the palm frond is the largest of these plants, the myrtle and willow are wrapped around it.
During Sukkot, the lulav and etrog are waved together while reciting special blessings. They are waved in each of the four directions – sometimes six if "up " and "down" are included in the ritual – representing God's dominion over Creation.