A locomotive is a powerful railway vehicle designed to pull trains along tracks. It contains a large engine that generates the necessary force to move heavy loads, such as passenger cars or freight containers. Locomotives can be powered by various sources, including diesel engines or electricity from overhead wires. Typically, locomotives are located at the front of a train, but they can also be positioned at the rear or in the middle. They are equipped with controls for the engineer, who operates the train. The design and technology of locomotives have evolved significantly since the first steam engines, making modern trains faster and more efficient.