Working of Reaction turbine:

In the impulse turbine the steam is expanded, causing pressure and heat drop in nozzle only and the moving blades only direct the steam through an angle. The impeller blades are symmetrical thus pressure of steam remains constant while passing over the blades. While in reaction turbines steam is expanded both in fixed and moving blades continuously as steam passes over them. So pressure drops gradually and continuously over both the moving and fixed blades. The blades of reaction turbines are symmetrical and thicker at one end that provides suitable shape for steam to expand.