Answer:
   
   A menorah is a 7-stick candle holder, typically with one holder higher
   or different than the others. It is one of the oldest symbols of the
   Jewish faith. It is mentioned in Exodus 25:31-40, which describes how
   to construct the menorah. the priests (kohanim) lit the menorah in the
   Sanctuary every evening and cleaned it out every morning, replacing
   the wicks and putting fresh olive oil into the cups.
   
   According to [5]www.jewfaq.org:
   
     The menorah is often considered a symbol of the nation of Israel
     and its mission to be "a light unto the nations." (Isaiah 42:6).
     The sages emphasize that light is not a violent force; Israel is to
     accomplish its mission by setting an example, not by using force.
     This idea is highlighted in the vision in Zechariah 4:1-6.
     Zechariah sees a menorah, and G-d explains: "Not by might, nor by
     power, but by My spirit."
     
   In synagogues, there is often a light above the ark, called the ner
   tamid (usually translated as the eternal flame). This symbolizes the
   menorah.
   
   In a menorah, one of the holders is typically higher or different than
   the others. This holder is called the shamash (head), and contains the
   candle used to light the other candles.
   
   Note: During Chanukkah, a nine-branched menorah is used. Technically,
   this is called a Chanukiah. It contains eight holders, one for each
   day of Chanukkah, plus the shamash.