Risk management refers to the practice of identifying potential risks in advance, analysing them and taking precautionary steps to reduce, curb or mitigate the risk.
A hazard is something that can cause harm, e.g. electricity, chemicals, dangerous surf conditions at a beach, working up a ladder, noise, a bully at work, stress, etc. A risk is the chance, high or low, that any hazard will actually cause somebody harm. For example, if you’re a poor swimmer and you swim in a rip (the hazard), there is a good chance you will get into trouble and may drown (the risk.)