Internal combustion refers to the process of burning fuel inside an engine to produce power. Some synonyms for this term include thermodynamic motor, reciprocating engine, and combustion engine. Another similar term is the internal combustion piston engine, which is commonly used in vehicles such as cars and motorcycles. Furthermore, the phrase "combustion-driven" can also be used to describe the process in which fuel is burned to generate heat and energy. Regardless of the specific term used, internal combustion is a widely-used method for powering machinery and transportation, and its continued use is likely to persist in the coming years.