The original menorah was of gold and stood in the Jewish Temple, as commanded in Exodus ch.25. It burned olive oil.
For the last 2200 years, another type of menorah is the ones that are lit during Hanukkah.
For most Jews, the centerpiece of Hanukkah is the Hanukkah-menorah, a nine-branched candelabrum, also sometimes called a Hanukkiah. As you look at a menorah, you will notice that one candle is set at a different level from the other eight. That one is called the Shammash, or helper candle. Jewish law states that the regular candles are for viewing and spreading the word of the miracle only, so the Shammash is used to light the others, and for any other purpose, such as for light to read by.
The menorah itself may be made in almost any manner - glass, aluminum or other metals. Menorahs may be sleek and contemporary, or flowery and ornate, and may incorporate decorations such as the Tree of Life.
The menorah should be placed in a manner that is as visible as possible to the public, to publicize the miracle of Hanukkah. Depending on custom, some families light the menorah in a doorway, or a window, or some other place that is highly visible.