In this lectures I will present a series of results from Nonlinear Potential Theory; these are concerned with estimates for solutions to nonlinear, possibly degenerate elliptic and parabolic equations. They are bound to reproduce, in the nonlinear case, the basic quantitative and qualitative properties of solutions to elliptic equations and harmonic functions. Fine properties and a priori regularity estimates follow. In will start from results about the classical local case, while I will conclude with new nonlinear potential estimates in the non-local case.