A cause is something that produces an event or condition; it is the reason why something happens. It refers to the source or origin of an event, phenomenon, or condition and is often identified as the agent or circumstance that produces an effect. For example, the cause of a car accident could be a mechanical failure, reckless driving, or bad weather. In scientific and philosophical inquiry, the concept of cause is central to understanding how the world works and why events happen as they do.