A shtiebel (Yiddish: שטיבל shtibl, meaning “little house” or “little room”) is a place used for communal Jewish prayer. In contrast to a formal synagogue, a shtiebel is far smaller and approached more casually. It is typically as small as a room in a private home or a place of business which is set aside for the express purpose of prayer, or it may be as large as a small-sized synagogue. It may or may not offer the communal services of a synagogue.
Traditionally a shtiebel is not only a place for prayer, but also a place for community gathering. Due to the prominence of a Hasidic Rebbe, the shtiebel served as a medium for being near to him. A shtibl would be host to the Shalosh Seudos, the ritual third meal of the Sabbath.
The Shtibl was common in Jewish communities in Eastern Europe before the Holocaust. It was popularly preferred to large synagogues by Hasidim, and continue to exist in contemporary Israel and the United States.
In Israel, minyans are held in many a storefront shtibl in major business areas around the clock; whenever ten men show up, a new minyan begins. (Source: Wikipedia)