Solar energy is a renewable energy source that can be converted into usable energy through solar panels. It is provided by the sun in the form of solar radiation, which is most abundant during the day. Solar energy is clean and renewable, and can be used to produce electricity through solar panels or heat water and homes. It has advantages of being free once the solar panels are installed and causing no pollution, but disadvantages include that it is not available at night and solar cooking requires direct sunlight. Solar energy can be classified as passive, active, photovoltaic, or concentrated, and used for applications like lighting, heating, cooling, electricity generation, and cooking.