The Jewish festival of Shavuot commemorates the anniversary of when God gave The Torah and the 10 commandments to the Israelites assembled at Mount Sinai. The holiday is one of the Shalosh Regalim, the three Biblical pilgrimage festivals. It marks the conclusion of the Counting of the Omer, and its date is directly linked to that of Passover. The Torah mandates the seven-week Counting of the Omer, beginning on the second day of Passover, to be immediately followed by Shavuot. This counting of days and weeks is understood to express anticipation and desire for the giving of the Torah. On Passover, the people of Israel were freed from their enslavement to Pharaoh; on Shavuot they were given the Torah and became a nation committed to serving God.
The word Shavuot means weeks
The festival of Shavuot marks the completion of the seven-week counting period between Passover and Shavuot. It is one of the less-celebrated Jewish holidays among secular Jews outside Israel and is celebrated for 2 days whereas those in Israel are more aware of it and celebrate it for 1 day. Reform Judaism celebrates only one day.