Core and periphery are terms used in geographic models to describe areas of differing economic production and political power and can be applied to both intra- and interstate variations. Core areas are described as the engines of economic growth and are characterized by modern, technologically advanced production methods as well as highly skilled and highwage labor. Places using low-technology production methods accompanied by low skill and low-wage labor, on the other hand, are labeled the periphery. Within the discipline of geography, the terms core and periphery are more common in the subdiscipline of political geography as compared to economic geography, where they have been deemphasized in favor of more complex notions of flows and processes. The concepts of core and periphery can be applied to various scales. At the interstate scale, examples of core areas are the United States, the countries of Western Europe, and Japan. In these countries goods are produced using technologically complex methods, wages are high, and the labor force is relatively educated and skilled. Countries like Cambodia, Bangladesh, and most of Sub-Saharan Africa are examples of the periphery, where technologically simple, labor-intensive, lowskill, and low-wage occupations predominate. These are broad generalizations and within a country there can be areas of core processes and areas of peripheral processes. In the United States, for example, Silicon Valley in California is a core area where high-technology businesses are clustered. Appalachia, on the other hand, is a peripheral area where technology is less complex and wages are low. Going down to even smaller scales, within a city core and peripheral areas can be spatially designated. In New York City, Wall Street and the financial district would represent a core area and some of the underdeveloped neighborhoods in the outer boroughs would be considered peripheral. Although core and peripheral areas are often mapped, they are not place-based phenomena, but rather are characterized by the production processes present. Therefore, where core and peripheral processes are located, as well as what constitutes core and peripheral processes, can change over time. In each particular historical era core processes are the most technologically advanced production methods present. In the 19th century, core processes were characterized by the industrialized mass production of goods, such as textiles, in places like Manchester, England. In the present day, however, textile production is a peripheral production process common in countries of the global south. More technologically advanced computer and financial businesses predominate in core areas.