Although many people know about Hanukkah they do not know its true meaning. Hanukkah is a Jewish holiday. It is celebrated usually between November and December. Its first day is actually on the 25th of the Jewish month Kislev. The Hebrew word “Hanukkah” means “Dedication.” Hanukkah lasts for eight days and nights. It is the festival of lights. In about 160 B.C. the Jewish people were taken over by Assyrians and forced from their homes. The Jews were ordered to worship Zeus and not their God. There was a Jewish resistance that regained control by killing the soldiers who were enslaving them. After killing the soldiers the ‘rebel’ Jews, now known as Maccabees, escaped to the mountains and then returned to Jerusalem. When they returned they resolved to burn a menorah for eight days to ‘cleanse’ the temple, but found that there was barely enough oil for one day. They still lit the menorah and miraculously the oil lasted for the full eight days. To celebrate this miracle and God’s faithfulness the Jewish people light a menorah for eight days every year. This is the celebration known as Hanukkah.

Hanukkah is the festival of lights and a joyous time for Jews. It's observed for eight days to mark the defeat of Seleucid Empire forces that prevented the Jewish people from observing Judaism. The festival starts from the twenty-fifth day of the Hebrew month of Kisleiv. By the kindling of lights--one on the first night, two on the second and so on--the eight-day festival is marked. Candles are lighted on a special candle holder called a Chanukkiyah or a Hanukkah menorah. This year the festival will be start on December 21 by lighting the first candle at sunset.

Source: http://www.orthodox-jews.com/jewish-religious-holidays.html