Although the broad use of the term modernization refers to the economic and political development of societies all over the world in the 20th and 21st centuries, in a more narrow sense the term stands for the large social transformations that took place in western Europe and its colonies starting in the early modern period. It culminated in the industrial revolution and various political revolutions, especially the American and the French revolutions, and then spread to the rest of the world. For this reason, modernization more broadly refers to an array of processes that may include industrialization, urbanization, bureaucratization, expanded educational opportunities, growth in literacy, and even democratization. However, the concept in its narrow sense does not refer to social change or societal evolution in general, but instead to a very short episode in world history. Since its inception, sociology has tended to focus on this short period of social transformation. Often, this focus is only on the most recent developments, as seen in discussions of individualization and postmodernization.