A revolution is a big turning point that completely changes how people live, govern, or think. It often challenges old systems and creates something new, whether in politics, society, science, or culture.
A reaction is the way people respond to those big changes. Some may welcome the change, but others may resist it, trying to protect traditions, power, or control. Reactions can shape whether a revolution succeeds or fails.
Reform happens when people see problems in society or government and work to make improvements. Instead of overthrowing the whole system, reformers push for gradual, lasting changes to make things better or more fair.