One of the oldest symbols of the Jewish faith is the Menorah, a seven-branched candelabrum (Candlestand) used in the Temple. The 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.
The Nine Branched Menorah used during Chanukah, also known as the Chanukiyah, is commonly patterned after this Menorah, because Chanukah commemorates the miracle that a day's worth of oil for this menorah lasted eight days.
The Chanukah Menorah (Chanukiyah) holds nine candles: eight candles, symbolizing the eight days for which there was enough oil after the consecration of the temple, and an extra candle called the "shamash", which is used for lighting the rest of the candles.
Chanukah candles may only be used in the Chanukiyah, and may not be used for any other purpuse.