What is the steam engine?

A steam engine converts heat energy from steam into motion, usually by pushing a piston or turning a turbine. Early practical steam engines were developed in the 18th century, especially by Thomas Newcomen and later James Watt, whose improvements beginning in the 1760s made engines far more efficient. Steam power transformed mining, manufacturing, transportation, and agriculture, and it powered locomotives and ships for decades. Steam turbines remain important today in electricity generation, even though many are driven by nuclear, coal, or gas heat sources. The steam engine is one of the classic inventions of industrial history.