Incident
Any unwanted, unplanned occurrence is called incident.
Accident
Any unwanted, unplanned event which leads to injury, damage or loss is called accident.
Near miss
An event which occur with out injury of person damage to property but has the potential to result in an accident. Any unwanted, unplanned event that has potential to cause harms damage or loss but did not do so.
Hazard
A hazard is a dangerous phenomenon, substance, human activity or condition.
Risk
Combination of the (probability) frequency of an undesirable event occurring and the severity level of its consequence.
A risk is a chance high or low that any hazard will actually cause somebody harm
Risk Assessment: A formalized process of identifying the risk that they generate and then either eliminate or controlling the risk.