This introduction presents an overview of the key concepts covered in this book. The book deals with capitalism's evolution within Western Europe and its offshoots, and its spread to the rest of the world after 1848. The spread of global capitalism has two dimensions, and they can be distinguished by means of an analogy. The increased globalization across the nineteenth century was due to a combination of factors, especially the new transportation and information technologies. Late-twentieth-century growth rates by the East Asian tigers and then China have set a modern standard of 'growth miracles' hard to beat, making impressive growth spurts in the past look pretty modest. During the few decades between about 1820 and the mid nineteenth century, global migrations changed dramatically. Emigration policies changed, from restricting outflows before, to adopting laissez-faire policies thereafter. The late nineteenth century also saw a large increase in the integration of international capital markets, and in the volume of international capital flows.