The term 'Chapters in World History' can be summarized by the four-letter word 'ERAS'. ERAS are periods of time in history that are characterized by certain events, developments, and changes. They are often used to divide up long stretches of time into more manageable chunks for study and analysis. Examples of ERAS in world history include the Ancient Era, the Middle Ages, the Renaissance, the Age of Exploration, the Industrial Revolution, and the Modern Era.