How does the ozone layer protect us from ultraviolet radiation from the sun?

The ozone layer made of gas which is O3 or three atoms of oxygen this layer located around stratosphere layer. This layer will help protect us from the harmful ray or UV radiation (Ultraviolet radiation {UV-B}). And how is this layer help us then. It will reflect back the light that came from the sun and that radiation or light travel here every 8 minute. These O3 will help clear out or protect us from the radiation by reflect it back to the space. For example take one piece of gl and stand outside in a sunny day then let the light reflect on the mirror and a light will reflect back right because of it property. That is exactly what ozone layer do. Even O3(ozone) help us protect from a harmful ray, but it is bad to our health.