Synagogue in Greek means a place for coming together, a meeting place, and that is what a synagogue (SIN-ah-gog) is. It is a building where Jews come together and pray to their God. In this way it is a lot like a Christian church. The most important difference is that there is no altar in a synagogue.
There is no altar because for Jews there was only one place where you could sacrifice to God, and that was in the big temple Solomon built in Jerusalem. When that temple was destroyed by the Babylonians, it was rebuilt under the Persians, and used until the time of the First Jewish Revolt. When Titus crushed the First Jewish Revolt in the 70s AD, he destroyed the temple in Jerusalem. Since that time, the Jews have mostly not offered sacrifices to their God.
The earliest synagogues were probably just the living rooms or courtyards of people’s houses. Later on people began to build special places just to meet. Most synagogues have a rabbi, a leader, who organizes things and runs the place, and gives people advice.
Many beautiful synagogues were built in the Islamic Empire. This is a picture of a very fancy one from Cordoba in southern Spain.
Learn by doing: visit a synagogue near your house
What’s a rabbi?
More about Yom Kippur