There are several types of trains, each designed for specific purposes. Passenger trains transport people between cities and regions, while freight trains carry goods and materials. High-speed trains, like the Shinkansen in Japan, travel at much faster speeds, making long-distance travel more efficient. Another category is commuter trains, which serve urban areas, helping daily travelers reach their workplaces. Light rail systems operate in cities, providing quick transit over shorter distances. Additionally, subways or metro systems are underground trains that help reduce traffic congestion in densely populated areas.