Plasma is a gas consisting of positively and negatively charged particles in approximately equal quantities. The sun emits radio waves. In addition, the sun produces a background radio flux which depends on frequency and varies in the course of the solar cycle. More information and Classifications of Radio Emissions. NOAA References for Indices of Global Geomagnetic Activity.
Solar flares occur near sun spots between areas of oppositely directed magnetic fields.
Solar flares are classified by their x-ray emissions. The classification of a solar flare is based on its x-ray energy output. M-class flares are larger and more rare. X-class flares are even less common and are considered to be major events. X Class Flare Flares which have a particular range of energy output of X-ray radiation.