A diesel locomotive is a type of train engine that uses a diesel engine for power. Unlike steam locomotives, which rely on coal or wood to produce steam, diesel locomotives convert diesel fuel into mechanical energy. This makes them more efficient and easier to maintain, as they do not require the extensive water and fuel supplies needed for steam engines. Diesel locomotives are commonly used in freight and passenger transport due to their reliability and power. They can operate on various tracks and are often seen pulling long trains across vast distances. Their design has evolved over the years, incorporating advanced technology for better performance and lower emissions.