What's A Menorah?

From Chabad:

"What is a Menorah?"

What Is a Menorah?

The word “menorah” is Hebrew for “lamp,” and generally refers to either the seven-branched golden candelabra that was lit every day in the Tabernacle, and then the Holy Temple in Jerusalem, or the eight-flamed lamp that is lit on the eight nights of the Jewish holiday of Chanukah. 

The Chanukah Menorah

In the second century BCE, the Holy Land was ruled by the Seleucids (Syrian-Greeks), who tried to force the people of Israel to accept Greek culture and beliefs instead of mitzvah observance and belief in G‑d. Against all odds, a small band of faithful Jews, led by Judah the Maccabee, defeated one of the mightiest armies on earth, drove the Greeks from the land, reclaimed the Holy Temple and rededicated it to the service of G‑d. When they sought to light the menorah, they found only a single cruse of olive oil that had escaped contamination by the Greeks. Miraculously, they lit the menorah, and the one-day supply of oil lasted for eight days, until new oil could be prepared under conditions of ritual purity. To commemorate and publicize these miracles, the sages instituted the festival of Chanukah.

Differences Between the Temple Menorah and the Chanukah Menorah

The design of the Chanukah menorah may (but need not) be similar to the original menorah, with some important differences:

- The menorah in the Holy Temple had seven branches, while the Chanukah menorah has eight (plus the shamash).

- The Temple menorah was made of gold, and the Chanukah menorah can be made of any (fire-safe) material

- The menorah in the Holy Temple was lit indoors, while the Chanukah menorah is lit outside, at the front door facing the street (though in many communities it is customary to light indoors near a door or window.)

- The menorah in the Holy Temple was lit during the daytime, while we light the Chanukah menorah after sundown, letting it burn into the night.

The Lubavitcher Rebbe, Rabbi Menachem M. Schneerson, of righteous memory, explains that there is significance to these differences. The number seven represents the natural order of the world, as reflected in the seven days of creation and the seven days of the week. Eight represents a step beyond nature: the supernatural, the transcendent. The Temple was a place of holiness and revealed G‑dliness, and the seven lights of the menorah were enough to light up the Temple and the world around it. Nowadays, there is more spiritual darkness in the world, and G‑dliness is concealed. We need to reach beyond the limitations of nature and tap into a higher level of holiness in order to illuminate the darkness outside. The eight lights of our Chanukah menorahs, burning in the night, transform the world into a G‑dly, light-filled place.

^ I really didn't know that there was a difference between the Temple Menorah and the Chanukah Menorah. ^

https://www.chabad.org/holidays/chanukah/article_cdo/aid/1358679/jewish/What-is-a-Menorah-Chanukiah.htm