The phenomenon of super conductance is quite fascinating due to enormous applications and hence intense research in this area attracted engineers, scientists and businessmen. In this Chapter, we will briefly elaborate the conversion of a normal conductor to a superconductor which is a fascinating material since its discovery as well as the role of critical temperature and critical magnetic field for the super phenomenon of superconductivity. A short historical journey of superconductors from 1911 to date is also the part of this chapter that started with the work of Onnes on extreme low temperatures in cryogenic laboratories. The difference between perfect conductor and superconductor, classification of superconductors and finally the fundamental properties of superconductors have been discussed precisely.