Rosh Hashanah commemorates the birthday of the universe, the day G‑d created Adam and Eve - the center of the universe.  It celebrates the Jewish and the World New Year. It begins at sundown on the eve of Tishrei 1 and ends after nightfall on Tishrei 2.

The central observance of Rosh Hashanah is blowing the shofar (ram’s horn) on both mornings of the holiday (except on Shabbat), which is normally done in synagogue as part of the day’s services.

Rosh Hashanah feasts traditionally include round challah bread (studded with raisins) and apples dipped in honey, as well as other sweet foods that symbolize our wishes for a sweet year. Other Rosh Hashanah observances include candle lighting in the evenings and desisting from creative work. (that's in every holiday so either it should be in every one or not even here . And if yes, it should be at the beginning of the observances.)

Together with Yom Kippur (which culminates 10 days of repentance), it is referred to as the Yamim Nora'im (Days of Awe, or High Holidays).