What is the Kaddush?
The Kiddush is a blessing which is recited over the wine or grape juice used in sanctifying the Shabbat (Sabbath) or other Jewish holidays.
The Kiddush has also been used to refer to to refreshments served (at home or at a synagogue) following a prayer service on Shabbat or Yom Tov.
Each holiday or service has a respective Kiddush. There is a Kiddush for Friday night services, Shabbat morning services, Holiday Eve Kiddush, and Holiday Morning Kiddush.
Basically, the Kiddush is used to beginning on Friday night (when the Sabbath begins). Kibbush is typically only used at home in order to sanctify the Sabbath. When used in a synagogue, it is only used used as a small celebration after normal services.