Fossil fuels are a type of non-renewable energy source that is formed from the remains of plants and animals that lived millions of years ago. They include coal, oil, and natural gas, and are widely used for energy production, transportation, and a variety of other applications. The extraction and use of fossil fuels has significant environmental impacts, including the release of greenhouse gases that contribute to climate change. As a result, there is an increasing focus on transitioning to more sustainable and renewable energy sources.