Fossil fuels are natural substances formed from the remains of ancient plants and animals buried under layers of sediment for millions of years. They include coal, oil, and natural gas, which are extracted and burned to produce energy for electricity, heating, and transportation. The combustion of fossil fuels releases carbon dioxide and other greenhouse gases, contributing to climate change and air pollution. As a result, there is a growing push towards renewable energy sources, such as solar and wind, to reduce our reliance on these finite resources and mitigate environmental impacts.