Kiddush
There are many things Jews do to celebrate Shabbat [see Shabbat (Celebrating Shabbat)].  The minimum way to celebrate is to say the blessing "Blessed are You, God, Who makes Shabbat holy."  The Talmud adds that the blessing should be said with a cup of wine. This is because wine makes people feel happy.  Because of this, the Friday evening meal in a Jewish home starts with a ceremony to say this blessing over a cup of wine.