Diesel-electric locomotives are powerful trains that use a combination of a diesel engine and electric traction. The diesel engine generates electricity, which powers electric traction motors that drive the wheels. This design allows for efficient operation and better performance, especially on long distances and heavy loads. These locomotives are commonly used in freight and passenger services due to their versatility and ability to operate without the need for overhead electric lines. They can be found in various configurations, making them suitable for different types of rail operations across the world.