Ballast is a material used to provide stability and balance to various structures, particularly in ships and trains. In ships, ballast is often water or heavy materials placed in the hull to lower the center of gravity, improving stability in rough waters. In trains, ballast consists of crushed stone or gravel placed under the tracks to support the weight of the train and prevent movement. In addition to maritime and rail applications, ballast is also used in construction and engineering projects. It helps to stabilize foundations and prevent shifting, ensuring that structures remain safe and secure over time. Properly designed ballast systems are essential for the performance and safety of these transportation modes.