Significance of Rosh Hashanah

Rosh Hashanah (literally "head of the year"), is the Jewish New Year. It is the first of the High Holidays or Yamim Noraim ("Days of Awe"), celebrated ten days before Yom Kippur. Rosh Hashanah is observed on the first two days of Tishrei, the seventh month of the Hebrew calendar. It is described in the Torah as יום התרועה a day of "Screaming" or Shouting .
Rosh Hashanah marks the start of a new year in the Hebrew calendar (one of four "new year" observances that define various legal "years" for different purposes as explained in the Mishnah and Talmud). It is the new year for people, animals, and legal contracts. The Mishnah also sets this day aside as the new year for calculating calendar years and sabbatical (shmita) and jubilee (yovel) years. Jews believe Rosh Hashanah represents either figuratively or literally the creation of the World, or Universe. However, according to one view in the Talmud, that of R. Eleazar, Rosh Hashanah commemorates the creation of man, which entails that five days earlier, the 25 of Elul, was the first day of creation of the Universe.
The Mishnah, the core text of Judaism's oral Torah, contains the first known reference to Rosh Hashanah as the "day of judgment." In the Talmud tractate on Rosh Hashanah it states that three books of account are opened on Rosh Hashanah, wherein the fate of the wicked, the righteous, and those of an intermediate class are recorded. The names of the righteous are immediately inscribed in the book of life, and they are sealed "to live." The middle class are allowed a respite of ten days, until Yom Kippur, to repent and become righteous; the wicked are "blotted out of the book of the living forever."
In Jewish liturgy Rosh Hashanah is described as "the day of judgment" (Yom ha-Din) and "the day of remembrance" (Yom ha-Zikkaron). Some midrashic descriptions depict God as sitting upon a throne, while books containing the deeds of all humanity are opened for review, and each person passing in front of Him for evaluation of his or her deeds.
The Talmud provides three central ideas behind the day:
"The Holy One said, 'on Rosh Hashanah recite before Me [verses of] Sovereignty, Remembrance, and Shofar blasts (malchuyot, zichronot, shofrot): Sovereignty so that you should make Me your King; Remembrance so that your remembrance should rise up before Me. And through what? Through the Shofar.' (Rosh Hashanah 16a, 34b)" This is reflected in the prayers composed by the classical rabbinic sages for Rosh Hashanah found in all machzorim where the theme of the prayers is the strongest theme is the "coronation" of God as King of the universe in preparation for the acceptance of judgments that will follow on that day, symbolized as "written" into a Divine book of judgments, that then hang in the balance for ten days waiting for all to repent, then they will be "sealed" on Yom Kippur. The assumption is that everyone was sealed for life and therefore the next festival is Sukkot (Tabernacles) that is referred to as "the time of our joy" (z'man simchateinu).