Each day of the eight days of Chanukah, a candle is lit, successively, so that on the first day – one candle is lit, then two candles on the eve of the second day, and so on. Yet, if you look at a menorah designed for Chanukah, there are nine candle holders. (Unless the menorah uses oil with tiny wicks, then there are nine repositories for the oil). The reason for a total of nine, is to have a place, usually in the center of the menorah, for the shamash (servant) candle, that is used to light all of the other candles. This candle is lit first; then, it shares its light with the other candles.
The tradition is reminiscent of the pasuk (verse), “In Thy light do we see light” (Psalm 36:10, JPS 1917 Tanach). H’Shem is the source of life, that bestows light upon us; we are connected, even dependent upon Him for every breathe we take. “For Thou dost light my lamp; the L-RD my G-d doth lighten my darkness” (Psalm 18:29, JPS). At the darkest time of the year, may we hope to be enlightened by H’Shem, by way of His emes (truth), and chesed (mercy), two key components of Chanukah; for His truth led us in the darkness against our enemies; and, through His mercy the few were able to defeat the many.