Solar flares are sudden bursts of energy and radiation from the surface of the Sun. They occur when magnetic energy that has built up in the Sun's atmosphere is released. This release can produce intense light and heat, which can affect space weather and impact satellites and communication systems on Earth. These flares are classified into different categories based on their strength, with the most powerful being classified as X-class flares. Solar flares can also lead to coronal mass ejections, which are large expulsions of plasma and magnetic fields from the Sun that can cause geomagnetic storms on Earth.