The Star of David (Magen David, "Shield of David") is a hexagram β two equilateral triangles, one pointing upward and one downward, overlaid to form a six-pointed star. As a piece of pure geometry, the hexagram has appeared across many unrelated cultures throughout history, used simply as a decorative or protective device with no specific connection to Jewish tradition at all β a reminder that the shape and its later specifically Jewish meaning are historically separable.
The two interlocking triangles are frequently read as representing the union of opposites: fire and water, masculine and feminine, the human reaching toward the divine and the divine reaching down toward the human. This general symbolic reading long predates, and exists independently of, the symbol's much later adoption as a specifically Jewish emblem.