Yom Ha'atzmaut (Hebrew: יום העצמאות yōm hā-‘aṣmā’ūṯ, lit. "Independence Day") commemorates Israel's declaration of Independence in 1948. It is celebrated on 5th of Iyar according to the Hebrew calendar. Yom Ha'atzmaut is preceded by Yom Hazikaron, the Israeli Fallen Soldiers and Victims of Terrorism Remembrance Day.
Yom Ha'atzmaut centres around the declaration of the establishment of the State of Israel by The Jewish Leadership led by future Prime Minister, David Ben-Gurion, on 14 May 1948. This was declared 8 hours before the end of the British Mandate of Palestine, which was due to finish on 15 May 1948.
The operative paragraph of the Declaration of the Establishment of State of Israel of 14 May 1948 expresses the declaration to be by virtue of our natural and historic right and on the strength of the resolution of the United Nations General Assembly. The operative paragraph concludes with the words of Ben-Gurion, where he thereby declares the establishment of a Jewish state in Eretz Israel, to be known as the State of Israel.
The new state was quickly recognised by the Soviet Union, the United States de facto, and many other countries, but not by the surrounding Arab states, who declared war.
An official ceremony is held every year on Mount Herzl, Jerusalem on the evening of Yom Ha'atzmaut. The ceremony includes a speech by the speaker of the Knesset (the Israeli Parliament), artistic performances, a Flag of Israel, forming elaborate structures (such as a Menorah, Magen David) and the ceremonial lighting of twelve torches, one for each of the Tribes of Israel.
Every year a dozen Israeli citizens, who made a significant social contribution in a selected area, are invited to light the torches. Many cities hold outdoor performances in cities' squares featuring leading Israeli singers and fireworks displays. Streets around the squares are closed to cars, allowing people to sing and dance in the streets.
The Chief Rabbinate has declared Yom Ha'atzmaut a Jewish holiday on which Hallel is recited. The Religious Zionist movement created a liturgy for the holiday which sometimes includes the recitation of some psalms and the reading of a portion of the Prophets (Haftarah) on the holiday morning.
Source: Wikipedia