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Why are solar wind and hydroelectric power considered renewable energy sources?

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Study how a series of gears in a waterwheel translates a stream's energy to a millstone — energy conversion Before the Industrial Revolution, power came from three main sources: humans, draft animals, and water.
The ingenuity people used in harnessing waterpower can be seen in this medieval-style mill. The waterwheel is turned by a stream and is connected to a shaft that leads into the building. At the other end of the shaft is a gear. The connection of a series of gears translates the power from the stream to a shaft that drives a millstone, which grinds flour from grain.
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Solar, wind, and hydroelectric power are classified as renewable energy sources because they are derived from natural processes that are continually replenished on human timescales.12

Solar power harnesses sunlight, an inexhaustible energy source that is abundantly available and naturally occurring.34
Wind power utilizes the kinetic energy of moving air, which is a naturally recurring atmospheric phenomenon.5
Hydroelectric power relies on the hydrologic cycle, where the movement of water is constantly renewed by natural evaporation and precipitation.6

In contrast, fossil fuels such as coal, oil, and natural gas are finite resources that require millions of years to form, making them nonrenewable. Because renewable energy sources produce little to no pollution or greenhouse gas emissions compared to fossil fuels, they are essential for sustainable energy production and mitigating the impacts of global warming.125