This is a two day festival which takes place fifty days after the first day of Passover, marking the time that the Jews received the Torah on Mount Sinai. Shavuot is also known as the festival or feast of Weeks.
During their escape from Egypt, Moses brought the Israelites to the foot of Mount Sinai, which was lush with plants and flowers - they had been in the dry desert for the last few weeks and so this was an amazing sight. On the third day of the Hebrew month Sivan, Moses was told by God to prepare his people for God's visit. The Jewish people cleansed their clothes and bodies. On the sixth day, they woke up to thunder and lightening. They heard God's voice as he spoke from the clouds and he gave Moses the Ten Commandments on two stone tablets.
Prayers are said, especially at dawn, to thank God for the Torah. Synagogues are decorated with plants and flowers, to remember Mount Sinai, and dairy meals are eaten. Some people also spend the first night of Shavuot studying the Torah.