It is long believed that any ordered phase may not exist in two dimensions (2D) due to the strong fluctuations. However recent discoveries during last decades have changed this picture drastically. A very intriguing question arises about the possibility of inducing superconducting correlations in 2D. Beside fundamental interests, it is proven that high temperature superconductivity also has two dimensional physics and very recently a 2D superconductor at the interfaces between certain insulators has been observed. Therefore a suitable answer can shine light on the pass-way to the consistent theory of high temperature superconductivity and heavy fermion interface superconductors. In this talk I first review the general properties of 2D superconductors beside some historical introduction. Then I will focus on our own contribution to the field consisting of proximity effect in graphene and other 2D systems. In particular I will discuss over the exotic proximity effect in MoS2 which we have found due to the interplay of exchange field with intrinsic spin-orbit interaction.