Rosh Hashanah is the Jewish New Year and it begins with the sound of a shofar (ram’s horn). Sweet foods are eaten in the hope of a sweet New Year and the ritual of Tashlich is performed. The Days of Repentance follow, when Jews think back over the past year and make amends for their sins.
Yom Kippur, the holiest day in the Jewish calendar, is know as the Day of Atonement. It is celebrated 10 days after Rosh Hashanah and ends when a shofar is heard. These high holy days are a time to right wrongs, reflect upon the previous year, fast and visit the synagogue.
Useful Documents –
Rosh Hashanah and Yom Kippur Glossary
World Festivals and celebrations calendar