Star of Moshiach

The Magen David is composed of 2 triangles and when they meet, it creates 6 corners. When the 6 corners (wings) are folded towards the center, they perfectly cover the center (the body). This hints to Sarfei Kodesh (Holy Angels), as it says, "6 wings 6 wings to each, 2 covering the eyes, 2 covering the legs, 2 to fly with" "שש כנפים שש כנפים לאחד, בשתים יכסה פניו ובשתים יכסה רגליו ובשתים יעופף".
The Magen David also symbolizes the seven days of the week. The center of the star, the most complete figure, being the Shabbat; the six outer triangles, the six week days.

The triangles symbolizes the Sefirot (Divine Emanations) and hints to Avodat HaShem, as it says, "On 3 things the world stands; on the Torah, on the Avoda (prayers), and on charity".

Each triangle also represents triple relations between HKB'H and Am Israel:
1. Relation between a king and nation (master and servant).
2. Relation between father and son
3. Relation between man and woman

Charity is a way a son respects his father and continues in the right path, as it says, "Our Heavenly Father gives charity, also you give charity". "מה הוא [אבינו שבשמים] גומל חסדים, אף אתה גומל חסדים". Charity is pulled from the top triangle Sefira of Keter Malchut to the bottom triangle to Sefira Chesed.

Prayer is the work of the servant to his master, when the servant speaks to his master, it's like a prayer, as it says, '"כעבדא קמי מריה", like a servant infront of his master. Prayer (Avoda) is pulled from Sefira Bina to Gevura.

Torah learning is the 'kiss' like a groom and a bride. When a person learns from the Torah from the Mouth of HaShem, it's as they are united and a 'kiss' is created between them. This was the character of Yaakov Avinu, zs'l, as it says, "וישק יעקב לרחל And Yaakov kissed Rachel (Imenu, a'h). Torah learning is pulled from Sefira Chochma to Tiferet.

When the Magen David is closed with top borders (above picture), it represents the 12 months. The center represents leap year, Adar II. Additionally, it symbolizes the position of the twelve tribes of Israel encompased around the Mishkan (Tabernacle) in the Midbar, the center is tribe of Levi, whom were situated closest to the Mishkan.

Nisan - Aries, Tribe of Yehuda, Keter Kehuna, Emunah
Iyar - Taurus, Tribe of Issachar, Bina, Happiness
Sivan - Gemini, Tribe of Zevulun, Hod, Innocence
Tamuz - Cancer, Tribe of Reuven, Gevura, Fear
Av - Leo, Tribe of Shimon, Malchut, Humbleness
Elul - Virgo, Tribe of Gad, Tiferet, Mercy
Tishrei - Libra, Tribe of Efraim, Yesod, Truth
Cheshvan - Scorpio, Tribe of Menashe, Chesed, Love
Kislev - Sagittarius, Tribe of Binyamin, Nesach, Trust
Tevet - Capricorn, Tribe of Dan, Chochma, Cancellation
Shvat - Aquarius. tribe of Asher, Keter Torah, Pleasure
Adar - Pisces. tribe of Naftali, Keter Malchut, Willingness
Inside center - Adar II - Tribe of Levi, Daat, Uniqueness

The Magen David also symbolizes the six Tzaddikim of Am Israel: Avraham, Isaac, Yaacov Avinu, Yoseph HaTzaddik, Moshe Rabenu, Aaron HaCohen, a'h. The center is the symbol of Moshiach, as it says in the prophecy of Balaam in Numbers 24:17..."There shall step forth a STAR out of Jacob, And a sceptre shall arise out of Israel."