The material of the previous two chapters allows us to shortly present some of the main elements of the qualitative theory of regular non-linear ordinary differential equations. This chapter studies several normal forms for planar systems, highlighting the main differences between local and global dynamics, between generic and non-generic dynamic phenomena—as heteroclinic, and homoclinic orbits, and limit cycles—and the associated (regular) bifurcations. It also presents applications on economics, in particular, to the benchmark Ramsey model, the possible dynamics of maximized Hamiltonian dynamic systems, and the difference between bifurcation and comparative dynamics analyses.