In this lecture we will talk about the concept of Strongly Dissipative Diffeomorphisms,a class of maps that were introduced by Pujals and Crovisier. These diffeos contract volume and has intermediate dynamics between a onedimensional dynamic and a general surface diffeomorphism. We will give a brief introduction of its basic concepts in the disc and in the n-ring, presenting the idea behind the graph construction that describes the dynamics, exploring a bit about how conjugacy on graphs imply a correlation in the original dynamics.