And God seeth all that He hath done, and lo, very good; and there is an evening, and there is a morning — day the sixth. And the heavens and the earth are completed, and all their host; and God completeth by the seventh day His work which He hath made, and ceaseth by the seventh day from all His work which He hath made. And God blesseth the seventh day, and sanctifieth it, for in it He hath ceased from all His work which God had prepared for making. (Book of Genesis)

Shabbat is the most important of Jewish celebrations. On Shabbat we give thanks to God for the creation, as prescribed by the fourth commandment.

The holiday begins before sunset on Friday evening, with the lighting of the candles, and lasts until the appearance of three stars in the sky on Saturday night.

On every Shabbat, we recite a blessing called Kiddush. In this blessing we thank God for having created the world, for having elected us among all peoples, and for having given us the Shabbat as a holy day. During the Kiddush, we bless a glass of wine and two loaves of a special bread called challah, which we share with family and guests. Wine is the symbol of joy, while the challah references the double portion of manna that the Lord gave the Jews in the desert.

Shabbat is also the day of rest. All work must be suspended, therefore agricultural work, housework, the lighting of a fire, travel and all forms of commerce are forbidden. 
The troubles of everyday life are forgotten on Shabbat, as Saturday is dedicated to study, prayer, and family.

Shabbat table