Hanukkah (also spelled as Chanukah, Chanukkah, or Chanuka), is known as the Festival of Lights, commemorating the re-dedication of the the Second Temple in Jerusalem at the time of the Maccabean Revolt of the 2nd century BCE. Hanukkah is observed for eight nights and days, starting on the 25th day of Kislev, which may occur at any time from late November to late December.
When the Temple was liberated and rededicated Judah ordered the Temple to be cleansed, a new altar to be built in place of the polluted one and new holy vessels to be made. According to the Talmud, olive oil was needed for the menorah in the Temple, which was required to burn throughout the night every night. The story goes that there was only enough oil to burn for one day, yet it burned for eight days, the time needed to prepare a fresh supply of oil for the menorah. An eight day festival was declared by the Jewish sages to commemorate this miracle.
The festival is observed by the kindling of the lights of a unique menorah, the nine-branched Hanukiah. Each night one additional light is lit, progressing to eight on the final night. The typical Hanukiah consists of eight branches with an additional raised branch. The extra light is called a shamash (translates to "attendant" or "sexton") and is given a distinct location, usually above or below the rest. The purpose of the shamash is to have a light available for use, as using the Hanukkah lights themselves is forbidden.
Typically three blessings (Brachah) are recited during this eight-day festival. On the first night all three blessings are recited, on subsequent nights only the second and thrid blessings are recited:
Baruch atah, Adonai Eloheinu, Melech haolam, shehecheyanu v'kiy'manu v'higianu laz'man hazeh.
Blessed are You, Adonai our God, Sovereign of all, for giving us life, for sustaining us, and for enabling us to reach this season.
Baruch atah, Adonai Eloheinu, Melech haolam, asher kid'shanu b'mitzvotav v'tsivanu l'hadlik ner shel Chanukah.
Blessed are You, Adonai our God, Sovereign of all, who hallows us with mitzvot, commanding us to kindle the Chanukah lights.
Baruch atah, Adonai Eloheinu, Melech haolam, she-asah nisim laavoteinu v'imoteinu bayamim hahaeim baz'man hazeh.
Blessed are You, Adonai our God, Sovereign of all, who performed wonderous deeds for our ancestors in days of old at this season.