A definition by Wikipedia
Western culture, sometimes equated with Western civilization, Occidental culture, the Western world, Western society or European civilization is a term used very broadly to refer to a heritage of social norms, ethical values, traditional customs, belief systems, political systems, and specific artifacts and technologies that have some origin or association with Europe. The term also applies beyond Europe, to countries and cultures whose histories are strongly connected to Europe by immigration, colonization, or influence. For example, Western Culture includes countries in the Americas and Australasia, whose language and demographic ethnicity majorities are currently European.
Western culture is characterized by a host of artistic, philosophic, literary, and legal themes and traditions; the heritage of Greek, Roman, Jewish, Celtic, Slavic, and other ethnic and linguistic groups, as well as Christianity including the Roman Catholic Church, and the Orthodox Church,which played an important part in the shaping of Western civilization since at least the 4th century. Before the Cold War era, the traditional Western viewpoint identified Western Civilization with the Western Christian (Catholic–Protestant) countries and culture.
A cornerstone of Western thought, beginning in ancient Greece and continuing through the Middle Ages and Renaissance and into modern times, is a tradition of rationalism in various spheres of life, developed by Hellenistic philosophy, Scholasticism, humanism, the Scientific revolution and the Enlightenment. Values of Western culture have, throughout history, been derived from political thought, widespread employment of rational argument favouring freethought, assimilation of human rights, the need for equality, and democracy.
Ancient Greece is considered the birthplace of Western culture, with the world’s first democratic system of government and major advances in philosophy, science, and mathematics. Greece was followed by Rome, which made key contributions in law, government, engineering and political organization. Western culture continued to develop with the Christianisation of Europe during the Middle Ages, the reform and modernization triggered by the Renaissance, and with globalization by successive European empires, that spread European ways of life and European educational methods around the world between the 16th and 20th centuries. European culture developed with a complex range of philosophy, medieval scholasticism, and mysticism, and Christian and secular humanism. Rational thinking developed through a long age of change and formation, with the experiments of the Enlightenment, and breakthroughs in the sciences. Tendencies that have come to define modern Western societies include the existence of political pluralism, prominent subcultures or countercultures (such as New Age movements), and increasing cultural syncretism resulting from globalization and human migration