Throughout the Bible sometimes we feel there is repetition of words, don't you? Well, during my Hermeneutics class I learned that every time there is repetition is because it is important. And from the beginning "Let there be light", the world, the earth did not have light. So God brought light first. Then when He is giving Moses instructions of His place of worship, He gives careful instruction of how precious that lamp should be. In the tent of the tabernacle there was no other light, just the lampstand.

Exodus 37:17-24   Making the Lampstand

So I looked around to find some more info about the Menorah and I came across these two. They mention why some have 6 branches and others 8. I encourage you to read it and then go and try to find an article about the meaning of the menorah and compare.

Menorah seven branched

 

The Menorah stood before the veil covering the entrance to the Holy of Holies. It is a Divine symbol that unites the whole panoply of meanings of the Number Seven - fullness, completion, perfection, and holiness - with the idea of the Light of God's Word. The perfect union of these ideas is astounding to behold. As with the Sabbath and the Number Seven itself, it begins in Genesis. The Menorah stands as an eternal memorial of the Seven Days when God created everything by the power of His Word and spoke His first command, "Let there be light." And just as the Menorah is called the Lamp of God (1 Sam 3:3), so also is God's Word twice referred to as a Lamp:

• Thy word is a lamp unto my feet, and a light unto my path. ...................... Psalm 119:105
• The commandment is a lamp; and the law is light...................................... Proverbs 6:23

 Source: http://www.biblewheel.com/topics/SevenfoldLight.asp     

Menorah  

One of the oldest symbols of the Jewish faith is the menorah, a seven-branched candelabrum 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 illustration at left is based on instructions for construction of the menorah found in Ex. 25:31-40.

It has been said that the menorah is a symbol of the nation of Israel and our mission to be "a light unto the nations." (Isaiah 42:6). The sages emphasize that light is not a violent force; Israel is to accomplish its mission by setting an example, not by using force. This idea is highlighted in the vision in Zechariah 4:1-6. Zechariah sees a menorah, and G-d explains: "Not by might, nor by power, but by My spirit."

The lamp stand in today's synagogues, called the ner tamid (lit. the continual light, usually translated as the eternal flame), symbolizes the menorah. Many synagogues also have an ornamental menorah, usually with some critical detail changed (for example, with only 6 candles) to avoid the sin of reproducing objects of the Temple.

The nine-branched menorah used on Chanukkah is commonly patterned after this menorah, because Chanukkah commemorates the miracle that a day's worth of oil for this menorah lasted eight days.

Source: http://www.jewfaq.org/signs.htm#Menorah