The Star of David (Magen David in Hebrew, literally Shield of David) is used as a symbol of Jewish communities, identity, and Judaism.
Its shape is a hexagram, made from two equilateral triangles.
The star appears occasionally in Jewish contexts since ancient times. In the past, it was also used by Christian, Muslim, and other communities. It was also known as ‘the seal of Solomon’. It may have been used for decoration or magical purposes. It was not distinctly Jewish. The idea of the Shield of David was not connected with the star at this time.
The Jewish community of Prague was the first to adopt the star as its symbol. In the 19th century, the symbol began to be widely used by Jewish communities across Eastern Europe. It has also been used by others to mark Jews, such as during the Holocaust.
Text adapted from English Wikipedia, Creative Commons Attribution-ShareAlike License 4.0.