The most widely used energy source in the world is fossil fuels, which include coal, oil, and natural gas. These energy sources account for a significant majority of global energy consumption due to their high energy density and well-established infrastructure for extraction, processing, and distribution. Fossil fuels are primarily used for electricity generation, heating, and transportation. However, their widespread use raises environmental concerns, including greenhouse gas emissions and air pollution. As a result, there is a growing shift towards renewable energy sources, such as solar, wind, and hydropower, to promote sustainability and combat climate change.