Hanukkah is the festival of lights. The eight day holiday celebrates the re-dedication of the Holy Temple in Jerusalem in 165 B.C.E. by the Maccabees, following a successful revolt against the Hellenist Syrians. Returning to the defiled Temple and facing the daunting task of restoring it to its former glory, the Jews found only enough pure oil to light the menorah for one day. Miraculously, the flame remained lit for eight days, just enough time to find more oil to maintain the fire.
Hanukkah is on the 25th of Kislev which usually falls in December.
Hanukkah is celebrated by lighting candles on a menorah. Each night one more candle is lit at sundown. It is a festive holiday with lots of celebrating.
All the traditional foods for Hanukkah revolve around oil, remembering the discovery of a single vessel of pure olive oil that burned miraculously for eight days. The two most traditional foods are Potato Latkes and Jelly Doughnuts (sufganiyot).
Some also serve dairy on Hanukkah because of Judith. Judith, a beautiful Jewish woman fed salty cheese to Nebuchadnezzar, king of the Assyrians general Holofernes. The cheese made him thirsty and he drank too much wine which caused him to fall into a drunken sleep. Judith cut off his head and the Israelis rallied and attacked the Assyrian armies who then fled.