In sociology, secularization (British English: secularisation) is a multilayered concept that generally denotes "a transition from a religious to a more worldly level." There are many types of secularization and most do not lead to atheism or irreligion, nor are they automatically antithetical to religion. Secularization has different connotations such as implying differentiation of secular from religious domains, the marginalization of religion in those domains, or it may also entail the transformation of religion as a result of its recharacterization (e.g., as a private concern, or as a non-political matter or issue).
The secularization thesis expresses the idea that through the lens of the European enlightenment modernization, rationalization, combined with the ascent of science and technology, religious authority diminishes in all aspects of social life and governance. Pew Research Center notes that economic development is positively correlated with less religiousness. According to Pippa Norris and Ronald Inglehart, "virtually all advanced industrial societies" have become more secular in recent decades.