What is Hanukkah all about ?

Hanukkah, also known as the festival of lights, celebrates the victory of the Jewish Maccabees over the Greek Seleucides in the 2nd century BCE, and the rededication of the Holy Temple of Jerusalem. The Greeks had desecrated the Temple, and when the Jews re-conquered it, they discovered that almost all the ritual olive oil had been profaned. There was only one sealed container left, just enough to last one single day. At the time, 8 days were needed to press new oil and make it ready for the Temple. They used the single container, and miraculously, it lasted for eight days.
To commemorate this miracle, starting on the 25th day of Kislev in the Hebrew calendar (sometimes between the end of November and the end of December in the secular calendar), Jews all over the world kindle the lights of a Hanukkiah (9 branches Menorah), one additional light on each night of the Holiday, until the eighth night.
There is no practical purpose to this lighting; its only goal is to diffuse light, which is synonym with joy in Judaism. Also,
it reminds symbolically of the Jewish identity: our ancestors fought not only for their life but also against the dangers of assimilation, and by lighting the candles, we too fight against assimilation.
To commemorate this miracle, starting on the 25th day of Kislev in the Hebrew calendar (sometimes between the end of November and the end of December in the secular calendar), Jews all over the world kindle the lights of a Hanukkiah (9 branches Menorah), one additional light on each night of the Holiday, until the eighth night.
There is no practical purpose to this lighting; its only goal is to diffuse light, which is synonym with joy in Judaism. Also,
it reminds symbolically of the Jewish identity: our ancestors fought not only for their life but also against the dangers of assimilation, and by lighting the candles, we too fight against assimilation.