Short answers, pulled from the story.
Nicolaus August Otto was a German engineer born on the 10th of June 1832 in Holzhausen an der Haide, Germany. He developed the four-stroke compressed charge internal combustion engine in 1876, the direct predecessor of every modern car engine. The Association of German Engineers formally defined this engine type as the "Otto Engine" in DIN Standard 1940.
The Otto cycle is a four-stroke sequence used in compressed charge internal combustion engines. The four strokes are: a downward intake stroke drawing in fuel and air, an upward compression stroke, a downward power stroke that ignites the compressed mixture, and an upward exhaust stroke that expels the burned gas. All engines that draw in a fuel-air mix, compress it, and ignite it by a timed spark are classified as Otto cycle engines under DIN Standard 1940.
Otto and Eugen Langen entered into a partnership on the 31st of March 1864, naming their firm NA Otto & Cie in Cologne. It was the first company in the world dedicated entirely to designing and producing internal combustion engines. The company later relocated and eventually became Deutz Gasmotoren Fabrik.
Over 50,000 engines were produced in the 17 years following the introduction of the four-stroke compressed charge engine in 1876. Before that, the earlier atmospheric engine had reached a production rate of 634 units a year by 1875, with 2,649 atmospheric engines built in total before production was discontinued in 1882.
Gottlieb Daimler, after leaving Otto's company, hired a lawyer to avoid paying royalties. The lawyer discovered a patent issued in 1862 to French engineer Beau De Rochas covering the concept of a four-cycle engine. Neither Otto nor Daimler had been aware of the Rochas patent; Rochas never actually built an engine. The discovery caused Otto to lose one of his key patents, freeing Daimler to sell engines in Germany without paying royalties to Deutz AG.
Otto's 1864 atmospheric engine won the gold medal at the 1867 World Exhibition in Paris. In 1882, the University of Wurzburg awarded him an honorary doctorate. His home was later converted into a museum promoted by local government, and in 1936 the Association of German Engineers enshrined his name in DIN Standard 1940, applying the term "Ottomotor" to all engines of that type.