The word "Shabbat Siddur" refers to the prayer book specifically used for Shabbat services. However, there are other terms that can be used interchangeably with Shabbat Siddur, depending on the Jewish community or denomination. In Orthodox Judaism, the term "Siddur" is commonly used as a general term for the prayer book used for all services, including those specific to Shabbat. In Conservative Judaism, the term "Shabbat prayer book" may be used. Additionally, in Reform Judaism, the term "service book" may be used, as it emphasizes the communal aspect of the service rather than the specific prayers being used. Regardless of the term used, the Shabbat Siddur is an important tool for worship and connection to Jewish tradition.