The steam engine is a machine that uses steam power to perform mechanical work through the agency of heat. The purpose of the steam engine is to convert energy into mechanical force or motion that can turn pistons and wheels. The steam engine was one of the most important technologies of the Industrial Revolution, and it played a significant role in the development of many industries. The steam engine was used in many industrial settings, especially mining, where the first engines pumped water from deep workings. Early mills had run successfully with water power, but by using a steam engine, a factory could be located anywhere, not just near water. Water power varied with the seasons and was not available at times due to freezing, floods, and dry spells. The steam engine improved productivity and technology and allowed the creation of smaller and better engines. After the development of the high-pressure engine, transport applications became possible, and steam engines were used in locomotives, steamboats, and other vehicles.