Derailment refers to the situation when a train or other rail vehicle leaves its tracks, often due to mechanical failure, track issues, or external factors. This can lead to accidents, causing damage to the train, infrastructure, and potentially resulting in injuries or fatalities. Preventive measures, such as regular maintenance of rail tracks and train systems, are essential to minimize the risk of derailment. Additionally, advancements in technology, like sensors and monitoring systems, help detect potential problems before they lead to a derailment, ensuring safer rail travel for passengers and cargo.