Why we call it "RISK" and how many types of RISK?

Risk a situation involving exposure to danger. There are various type of risks.

RISK is expose (someone or something valued) to danger, harm, or loss.

"The effect of uncertainty on objectives" ISO31000

Thus Risk can be defined as the occurrence of any probable event or change circumstance resulting in negative, positive or uncertain impact.

According to the impact nature risks may be divided into three categorize 

•A bad negative impact              Hazard (or pure) risks

Example:  The1:5000 chance of having a car accident

•Uncertain impact…..Control risks

Example: The uncertainty in delivering a project on time, within budget and to specification.

•A positive reward or profit….Opportunity (or speculative) risks

Example: The chance of making a profit from an investment.

Risk is a factor which can influnce negative but can be positive to drag work/project into wrong directions

In business context risk can be fdefined as " A probability or threat of damage, injury, liability, loss, or any other negative occurrence that is caused by external or internal vulnerabilities, and that may be avoided through preemptive action".  There are macro and micro economic risks, depending on the industry in which the business operates.