Many know the chanukiyah as a menorah, but there's actually a large difference in the two pieces of Judaica.
Menorah vs. Chanukiah
Both items are a type of candelabra, but the chanukiah has nine branches while the menorah has only seven. The chanukiah has eight candles in a row with a ninth candle separated or raised (depending on the style of the candelabra) and they come in all shapes, sizes, and themes. The chanukiah represents the miracle of Chanukah when, during the rededication of the Temple, the oil that should have lasted just one night lasted for a miraculous eight nights.
The ninth branch, known as the shamash ("helper" or "servant"), on the chanukiah is used to light the other branches during each night of Chanukah. Each night of Chanukah the shamash is lit first and then the candles are lit one by one for each night, from left to right (unless you follow another tradition or opinion).
The other candelabra, known as the menorah, is more of a symbolic object in Judaism. Dating to the time of the First Temple in Jerusalem, it comprises seven branches and does not have a shamash. The menorah was lit by the priests (kohanim), using olive oil every evening in the Holy Temple.
"And you must make a lamp-stand of pure gold. Of hammered work the lamp-stand is to be made. Its base, its branches, its cups, its knobs and its blossoms are to proceed out from it. And six branches are running out from its sides, three branches of the lamp-stand from its one side and three branches of the lamp-stand from its other side. Three cups shaped like flowers of almond are on the one set of branches, with knobs and blossoms alternating, and three cups shaped like flowers of almond on the other set of branches, with knobs and blossoms alternating. This is the way it is with the six branches running out from the lamp-stand. And on the lamp-stand are four cups shaped like flowers of almond, with its knobs and its blossoms alternating. And the knob under two branches is out of it and the knob under the two other branches is out of it and the knob under two more branches is out of it, for the six branches running out from the lamp-stand. Their knobs and their branches are to proceed out from it. All of it is one piece of hammered work, of pure gold. And you must make seven lamps for it; and the lamps must be lit up, and they must shine upon the area in front of it. And its snuffers and its fire holders are of pure gold. Of a talent of pure gold he should make it with all these utensils of it. And see that you make them after their pattern that was shown to you in the mountain." (Exodus 25:31-40)
This candelabra became known as a symbol of Judaism and can be found in nearly every synagogue around the world in the form of the ner tamid or everlasting light. In most synagogues, above the arc where the Torah is kept there is a light that is always kept on that represents the holy menorah from the Temple period. The ner tamid reminds us of the Holy Temple and the sadness of its destruction. Whereas it used to be a constantly lit flame, it is now typically an electric lamp that stays on at all hours of the day.
As you can see, the difference in the two items is significant. Whereas the chanukiah is used for the celebration of a specific festival, the menorah is more of an everlasting symbol of the Jewish religion.
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