Hanukkah starts tonight. Here's what you need to know about the Jewish holiday.

This evening will mark the beginning of Hanukkah, the Jewish festival of lights.

As millions of Jews prepare for the eight-day celebration, which starts at sundown, here are some important facts about the holiday, including its origins.

What is Hanukkah?

Hanukkah means “dedication” in Hebrew. The eight-day holiday celebrates the rededication of the Temple of Jerusalem after it was retaken by the Maccabees, a group of Jewish warriors, from the Greeks in the 2nd century BCE, as explained by Tablet magazine.

It is one of the few Jewish holidays not mentioned in the Hebrew bible, instead being detailed in writings known as the Apocrypha, according to ReformJudaism.org.

So why is it celebrated for eight days?

After reclaiming the Temple, there appeared to be just enough oil inside the house of worship to light a lamp inside for a single day, wrote MyJewishLearning.com. But miraculously, that tiny bit of oil actually lit the Temple for eight days, which is how long the holiday lasts.

The holiday will start today at sundown and end on the evening of Dec. 20 this year.

Jewish holidays begin at sundown because the religion follows a lunar calendar.

How is it celebrated?

The Jewish celebration is centered around the menorah, a candlestick that is the most recognizable symbol of Hanukkah.

The celebration starts with lighting just one candle on the menorah on the first night of the holiday as a blessing is said, then on the second night two candles are lit, and on the third three candles, until all eight are lit on the last night. There’s a ninth candle in the middle of the menorah called the shammash, which is used to light all the other candles.

The lit menorah is often placed on a window sill or someplace visible to the public, according to the Independent.

There are other traditions, too: eating fried foods like latkes, spinning the dreidel, and winning prizes (or chocolate coins called “gelt,” the Yiddish word for money) to the younger members of the family. Also, gifts are often given to children every night, likely due to the “influence of Christmas,” My Jewish Learning wrote.

What are dreidels and latkes?

Dreidels are spinning tops with four sides, with letters on it that stand for “a great miracle happened there,” referring to the Maccabees victory at the Temple. The dreidel game can be played with as many or as few people as you want.

In the game, everyone starts with an equal number of pieces like gelt or pennies or candy, according to My Jewish Learning. Participants place one of those pieces in the center at the start of every round, and then spin their dreidel — and then take pieces or put more in the middle depending on which letter the dreidel lands on.

Here’s a video that explains the game.

Latkes are fried potato pancakes, made from potatoes and eggs and fried in oil, in honor of the holiday. They are sometimes eaten with applesauce and sour cream.

Any other traditional Hanukkah food?

Yep! There’s donuts — called sufganiyot in Hebrew — that are filled with either custard or jelly, deep-fried and sprinkled with sugar on top for good measure.

Some people eat dairy, and specifically cheese, to honor Judith, a heroine who used her cheese and wine to lull an enemy general to sleep before killing him, according to Tablet. If you celebrate, you might also munch on some brisket, too.

This story was originally published December 12, 2017 at 9:41 AM with the headline "Hanukkah starts tonight. Here's what you need to know about the Jewish holiday.."