Flight cancellation occurs when an airline decides to not operate a scheduled flight. This can happen for various reasons, including bad weather, technical issues with the aircraft, or low passenger numbers. When a flight is canceled, passengers are typically notified in advance and may be offered alternative travel arrangements or refunds. Airlines are required to inform passengers about cancellations as soon as possible. Depending on the circumstances, travelers may be entitled to compensation under certain regulations, such as those set by the European Union or U.S. Department of Transportation. It's important for passengers to check their airline's policies regarding cancellations.