Diesel trains are locomotives powered by diesel engines, which convert fuel into mechanical energy. They are commonly used for both passenger and freight transport due to their efficiency and ability to operate on tracks without the need for electrification. Diesel trains can be found in various configurations, including diesel-electric and diesel-hydraulic systems, each offering different advantages in terms of power and maintenance. These trains are popular in many countries because they can travel long distances without needing frequent refueling. Additionally, diesel trains are often more cost-effective to operate than electric trains, especially in regions where building electrified railways is not feasible.