Within the Jewish faith, Hanukkah is one of the few vacations that isn't always instituted inside the Torah. It commemorates a publish-biblical event: the victory of the Maccabees over the Syrian-Greek rulers of Jerusalem and the following rededication of the Temple in 164 BCE.
It also celebrates a miracle that accompanied this occasion: while the temple changed into rededicated, God miraculously made the only day's really worth of oil burn brightly for eight days.
Hanukkah can be the Jewish excursion with which non-Jews are maximum acquainted, because of its proximity to Christmas. It isn't, however, the "Jewish Christmas" - it traditionally predates Christmas and is a very unique celebration.