Neutrinos in Hot and Dense Media

We reinvestigate the modifications in the properties of neutrinos in hot and dense media. The change in properties depends on the type of neutrinos. Massless neutrinos of the standard model acquire Dirac type of temperature and density dependent selfmass in hot and dense media. Dirac neutrinos exhibit the refractive energy and higher value of the magnetic moment in hot and dense media. The transition magnetic moment of Majorana neutrino is modified differently in hot and dense media. We compare all these changes in detail.