During the time period covered in this chapter, there were many forces of change. Exploration. Industrialization. Education. The continuing impact of the Enlightenment. The end of slavery. Military superiority. Nationalism. Imperialism. Racism. Capitalism. Marxism. It's mind-boggling.
What's more, these changes were communicated more quickly than ever before. Trains and ships raced across continent and sea. Telegraph cables were laid. By 1914, planes were in the air and telephones were ringing. Think about how much more quickly Japan industrialized than England. Think about how much more quickly Africa was colonized than Latin America. Increases in transportation and communication had far-reaching consequences.
Urbanization, too, fueled change. As people came in closer contact with each other, ideas spread more quickly. Like-minded people were able to associate. Individuals had contact with a greater variety of people, and therefore were exposed to a greater variety of ideas. Increasingly, developments in the cities raced along at a faster pace than those in villages and on farms. In India, for example, British imperialism greatly impacted life in the cities. Indians learned to speak English and adopted European habits. In the countryside, however, Hindu and Muslim culture continued along largely uninterrupted.
Of course, most change-even "revolutionary" change-didn't entirely supplant everything that came before it. For example, the Scientific Revolution challenged some assertions made by Roman Catholicism, but both survived, and many people learned to be both scientific and Christian. Slavery was successfully outlawed, but that of course didn't mean that former slaves were suddenly welcomed as equals. Racism, both social and institutional, continued.
It's also important to keep in mind that individuals, even those who were the primary agents of change, acted and reacted based on multiple motives, which were sometimes at odds with each other. The United States declared its independence eloquently and convincingly, and then many of the signers went home to their slaves. Factory workers argued tirelessly for humane working conditions, but once achieved, happily processed raw materials stolen from distant lands where the interests of the natives were often entirely disregarded.
Change is indeed very complex, but it's also impossible to ignore. Life for virtually everyone on the globe was different in 1914 than in 1750. If you can describe how, you're well on your way to understanding the basics. If you can describe why, you're on your way to doing well on the exam.