"Folk religion" (sometimes called "popular religion") refers to the practice of local religious customs that deviate from the orthodox practices of the major religions to which adherents nominally belong. In many cases, such regional variations arise from syncretism, or the blending of multiple religions, especially in colonial contexts, but other aspects of folk religions simply develop in reaction to changing community dynamics over time. All major religions embrace some level of regional variation but they differ in terms of how much variation and what types of variation are deemed acceptable under official doctrine.