Modernization theory is a theory used to explain the process of modernization within societies. The theory looks at the internal factors of a country while assuming that, with assistance, "traditional" countries can be brought to development in the same manner more developed countries have. Modernization theory attempts to identify the social variables which contribute to social progress and development of societies, and seeks to explain the process of social evolution. Modernization theory not only stresses the process of change but also the responses to that change. It also looks at internal dynamics while referring to social and cultural structures and the adaptation of new technologies.
Dependency theory is a body of social science theories predicated on the notion that resources flow from a "periphery" of poor and underdeveloped states to a "core" of wealthy states, enriching the latter at the expense of the former. It is a central contention of dependency theory that poor states are impoverished and rich ones enriched by the way poor states are integrated into the "world system."
The theory arose as a reaction to modernization theory, an earlier theory of development which held that all societies progress through similar stages of development, that today's underdeveloped areas are thus in a similar situation to that of today's developed areas at some time in the past, and that therefore the task in helping the underdeveloped areas out of poverty is to accelerate them along this supposed common path of development, by various means such as investment, technology transfers, and closer integration into the world market. Dependency theory rejected this view, arguing that underdeveloped countries are not merely primitive versions of developed countries, but have unique features and structures of their own; and, importantly, are in the situation of being the weaker members in a world market economy.
Well, do people buy cell phones in developing countries? Well, if you were a global corporation would you want to expand your markets where there are more people to buy your wares? If you were a global corporation would you exploit the very low wages of low income nations to make your phones? Think about some of these questions, and find a large company to focus on. I think that Apple would be one good company to mention, as would Ford. Where are the manufacturing companies that produce industrial waste sites located?