Chanukah (also spelled Chanuka, Hanuka, Hanukka, Hannukah or Hanukkah) is the Jewish Festival of Lights, the Feast of Consecration, or the Feast of the Maccabees.
The story of Chanukah begins in 167 B.C. while Jerusalem was ruled by the Greek Empire. King Antiochus the 4th forced the Jews to reject their religion and to worship the Greek gods instead. As a result, the Jews began a revolt, Judas Macabeus being the leader. Chanukah celebrates the rededication of the temple in Jerusalem, after 3 years of fighting against the Greeks (Chanukah in Hebrew means "dedication").
Chanukah also commemorates the miracle of the oil cruse: According to tradition, after cleaning up the temple, the Maccabees found a very small amount of oil, just enough to light the Menorah for one day. Miraculously, the small cruse of oil that was found, lasted for 8 days, which is why the Chanukah celebration lasts 8 days.
The first evening of Chanukah starts after the sunset of the 24th day of the Hebrew month of Kislev (which takes place sometime in December). That is the date in which the Jewish army of Judas Macabeus and his brothers finished cleansing the temple of the Greek sculptures.
Every evening during Chanukah it is customary to light an extra candle in the Chanukiyah, a special Chanukah Menorah, in memory of the miraculous oil cruse. This miracle also led to the practice of eating fatty pastries such as "Sufganiot" (fried doughnuts filled with jam) and "Levivot" (potato fritters eaten with powdered sugar).
In addition, Chanukah is linked with the custom of children playing a special game with the Chanukah Dreidel.