Flares are generated from electromagnetic radiation which is sudden libratory of the stored energy in the magnetic field of the sun. These electromagnetic radiations vary from X ray to gamma ray. Flares are classified according to their brightness as C, M and X, where X is the brightest. X class flares cause long-time solar storm and ionospheric radio waves scintillations. Moderate level M class flares mostly effect polar cups and cause short-time radio scintillations. C class flares are weaker than the X and M flares. Their efficiency on Earth's ionosphere creates faint disturbances.