This chapter focused on discussing and defining penetration testing and why it is needed. On the basis of this definition, the PTES framework is described, which provides a new assessor the means to build his/her knowledge within a context of what an actual engagement would look like. To validate this knowledge, we explored how an example engagement breaks out across the major execution phases. Finally, the major tools used in a variety of assessments are listed and explained, many of which will be further explained with realistic examples in the following chapters. Now that you have an understanding about penetration testing and its methodology, we are going to start learning how powerful Python really is and how easy it is to get it up and running.