Sun spots are the dark spots which are present on the visible disk when the snaps of sun are taken in the presence of white light. These black spots have low temperature than that of their surrounding surface. This is the reason that they appears in dark color. Their count is not fixed. It changes with time. It can be increased or decreased. The regular activity of sun spots occur after 11 years. That particular period is called as sun-spot-cycle. These sun spots have very high magnetic fields of approximately 2000 to 3000 gauss. When this activity occurs then there is a possibility in which the surrounding parts of some sun spots become brighter. These bright regions are called as solar flares. When these flares are produced then large no of protons, electrons, and alpha particles are emitted. These produced particles results in radio as well as magnetic disturbances on the whole earth. It is a fact that the solar flares also affect the growth of plants.
The term solar activity is related to those activities that are taking place on sun. In simple words, the activity that is taking place on the surface of sun is called as solar activity.
