This document provides an overview of key concepts related to revolution, reaction, and reform in history. It defines revolution as a sudden or momentous change in a situation and lists examples of how the prefix "rev" is used to describe related concepts like revolving, revolutionizing, and reversing situations. It then discusses reaction as a response to new ideas or theories, and gives civil disobedience and non-violent reaction as examples. Finally, it defines reform as improving or correcting errors, problems, or injustices through actions like repairing, removing obstacles, or renewing methods.