1) https://en.wikipedia.org/wiki/Risk
Risk is the potential of gaining or losing something of value. Values (such as physical health, social status, emotional well-being or financial wealth) can be gained or lost when taking risk resulting from a given action or inaction, foreseen or unforeseen. Risk can also be defined as the intentional interaction with uncertainty. Uncertainty is a potential, unpredictable, and uncontrollable outcome; risk is a consequence of action taken in spite of uncertainty.
Risk perception is the subjective judgment people make about the severity and probability of a risk, and may vary person to person. Any human endeavor carries some risk, but some are much riskier than others.