Western culture, also known as Western civilization, European civilization, Occidental culture, or Western society, includes the diverse heritages of social norms, ethical values, traditional customs, belief systems, political systems, artifacts and technologies of the Western world. The core of Western civilization, broadly defined, is formed by the combined foundations of Greco-Roman civilization and Western Christianity. While Western culture is a broad concept, and does not relate to a region with fixed members or geographical confines, it generally relates to the cultures of countries with historical ties to a European country or a number of European countries, or to the variety of cultures within Europe itself. However, countries toward the east of Europe are sometimes excluded from definitions of the Western world.