A synagogue (from ancient Greek: transliterated "assembly"; Hebrew: beit knesset, "house of assembly"; Yiddish: Ladino: esnoga) is a Jewish house of worship.
The Hebrew term for synagogue is Beit Knesset or "House of Assembly," not to be confused with the Knesset, which is the Israeli parliament. Some congregations use the term Beit Tefila or "House of Prayer."
Synagogues usually have a large hall for prayer (the main sanctuary), smaller rooms for study, and sometimes a social hall and offices. Some have a separate room for Torah study, called the Beit midrash or "House of Study."
Before the destruction of the Second Temple in 70 CE, communal prayers centered around the korbanot or "sacrificial offerings" brought by the kohanim or "Jewish priests" in the Holy Temple. The all-day Yom Kippur service, in fact, was an event in which the congregation both observed the movements of the kohen gadol or a "Jewish high priest" as he offered the day's sacrifices and prayed for his success.
The destructions of Solomon's Temple, and later the Second Temple, and the dispersion of the Jews into the Jewish diaspora, threatened the nation's focus and unity. At the time of the Babylonian captivity, the Men of the Great Assembly began the process of formalizing and standardizing Jewish services and prayers that would not depend on the functioning of the Temple in Jerusalem. Rabbi Yohanan ben Zakkai, one of the leaders at the end of the Second Temple era, promulgated the idea of creating individual houses of worship in whatever locale Jews found themselves. This contributed to the concept of "portable Judaism," which was part of what contributed to the saving of the Jewish people by maintaining a unique identity and way of worship, according to many historians. Thus, even now, whenever any group of ten men comes together, they form a minyan, and are eligible to conduct public prayer services, usually in a synagogue.
Jewish men are required to pray three times a day, ideally with a minyan, i.e., a prayer quorum of ten adult men. Although prayers can be recited anywhere, the primary purpose of the synagogue is to facilitate this communal prayer. On the Shabbat and holidays, praying as a group becomes more important. Most Orthodox and many Conservative synagogues host prayer services every day. Some schedule a morning service and a combined afternoon-evening service to accommodate working people. A lesson in Mishna or other text may take place between the afternoon and evening services. Larger (particularly Orthodox) synagogues schedule multiple morning, afternoon, and evening services at different times to accommodate the varying schedules of their many congregants. Special services are held on Shabbat and Jewish holidays, with larger (particularly Orthodox) synagogues having several simultaneous or overlapping services in different rooms of the synagogue, geared to different groups (e.g. early risers, families, children, young adults). Reform congregations generally hold prayer services on Friday nights.
In addition to being a place of prayer, the synagogue also fulfills the necessary role of housing Torah scrolls, which are also needed for certain of the prayers. These holy religious articles need to be kept in a place of respect – this being the Holy Ark in a synagogue. Special rules apply to the removal of Torah scrolls from a synagogue.
The architectural shapes and interior designs of synagogues vary greatly. Other local religious buildings and national culture usually influence synagogue architecture.
Traditional and Orthodox synagogues
Orthodox Judaism has considered synagogue construction over the last two thousand years as following the outlines of the original Tabernacle, which was also the outline for the temples in Jerusalem. The Orthodox synagogue usually contains the following features:
An ark – called the Aron Ha-Kodesh, the Holy Ark by Ashkenazim and heikhal [temple] by Sephardim – where the Torah scrolls are kept. The Ark in a synagogue is positioned in such a way that those who face it, face towards Jerusalem. Thus, sanctuary seating plans in the Western world generally face east, while those east of Israel face west. Sanctuaries in Israel face towards Jerusalem. Occasionally synagogues face other directions for structural reasons; in such cases, some individuals might turn to face Jerusalem when standing for prayers, but the congregation as a whole does not. The ark is reminiscent of the Ark of the Covenant which contained the tablets with Ten Commandments. This is the holiest spot in a synagogue, equivalent to the Holy of Holies. The ark is often closed with an ornate curtain, the parokhet, outside or inside the Ark doors. A large, raised, reader's platform called the bimah- by Ashkenazim and tebah by Sephardim, where the Torah scroll is read and from where the services are conducted in Sephardi synagogues. A continually-lit lamp or lantern, usually electric, called the ner tamid, the "Eternal Lamp," used as a reminder of the western lamp of the menorah of the Temple in Jerusalem, which remained miraculously lit always. A candelabrum specifically lit during services commemorating the full Menorah. A pulpit facing the congregation for the use of the rabbi, from and a pulpit or amud- (Hebrew for "post" or "column") facing the Ark where the Hazzan stands while leading the prayer service.
A synagogue may be decorated with artwork, but in the Rabbinic and Orthodox tradition, three-dimensional sculptures and depictions of the human body are not allowed, as these are considered akin to idolatry. Synagogue windows are often curved at the top and squared at the bottom, recalling the popular depiction of the shape of the Lukhot (Tablets of the Law) which Moses received from God at Mount Sinai. There is also a tradition to install twelve windows around the main sanctuary to recall the Twelve Tribes of Israel, underscoring the importance of unity and brotherhood as a result of the communal prayers.