The word accident should be used when describing a situation that occurred unexpectedly and led to harmful consequences like damage or injury. It often carries an implication that the event was unforeseen, undesired, and usually unavoidable through normal precautions. It is frequently used in the context of traffic collisions, workplace injuries, or other scenarios where harm or loss occurs without malicious intent.

The term incident is applicable to a wide range of situations that describe any event, especially one that is unusual or significant. It doesn't necessarily imply that any harm was done but indicates a notable occurrence. Incidents may be used in reference to altercations, malfunctions, or deviations from normal operations, and can be planned or unplanned.

While both accident and incident refer to events that disrupt normal proceedings, the key difference lies in the nature and ramifications of the event itself. An accident implies harm or loss stemming from an unintended occurrence, whereas an incident is a more inclusive term for any significant event, which may not necessarily result in damage or harm. Understanding this distinction enhances clarity and precision in communication, particularly in emergency response, healthcare, and safety contexts.