https://en.wikipedia.org/wiki/Western_world

The concept of the Western part of the earth has its roots in Greco-Roman civilization in Europe, and the advent of Christianity.[2][3][4][5][6] In the modern era, Western culture has been heavily influenced by the traditions of the Renaissance, Protestant Reformation, Age of Enlightenment—and shaped by the expansive colonialism of the 15th-20th centuries. Before the Cold War era, the traditional Western viewpoint identified Western Civilization with the Western Christian (Catholic-Protestant) countries and culture.

Christianity remains the dominant religion in the Western world, where 70% are Christians.[38]