The Festival of Shavuot is one of the oldest Jewish holidays and one of the three most important, the Shalosh Regalim: Passover, Shavuot, and Sukkot.
Shavuot is celebrated seven weeks exactly from Pesach Sheni ("Second Passover").
Shavuot essentially "completes" Passover in that Passover marks the physical exodus of the people of Israel from slavery in Egypt, while their journey of spiritual exodus is completed only on Shavuot: on this day, at Mount Sinai, God delivers the Torah and with it the highest of moral and ethical codes. As such, Shavuot is also called Chag Matan Torah (the holiday of the giving of the Torah).
The Festival of Shavuot has many names: Pentecost (fiftieth day), Chag HaKatzir (Festival of Reaping), Chag Matan Torah, the Festival of Shavuot, Yom Habikkurim (Day of First Fruits), Chag Atzeret (literally "refraining"), Yom HaKahel (Day of Solemn Assembly).
The mention of the holiday in the Scriptures as well as the custom of bringing the first fruits is eternalized in two songs by the composer, musician, and Israel Prize recipient Yedidya Admon (1894-1982) – "VaChag Shavuot Ta'ase Lecha" and "Saleynu Al Ketefeynu" with lyrics by Levin Kipnis.