A diesel-electric locomotive is a type of train engine that uses a diesel engine to generate electricity. This electricity powers electric traction motors that drive the wheels of the locomotive. This design allows for efficient power transfer and can provide high torque at low speeds, making it suitable for heavy freight and passenger services. These locomotives are commonly used in rail transport due to their versatility and lower emissions compared to traditional steam engines. They can operate on tracks without the need for external power sources, making them ideal for long-distance travel and remote areas where electric infrastructure is limited.