Energy security has been assessed as a multi-dimensional concept with a holistic approach and elaborated in terms of all its aspects in this book. As per the broadest approach, it was pointed out that energy security is the process whereby energy sources and countries of origin are diversified taking into account the political and economic conditions of the said countries, and wherein continual and affordable pricing mechanisms are developed within a sustainable (environment-friendly) systematic. It was also mentioned that generation, transmission and distribution activities need to be continued while ensuring a controlled and sustained energy infrastructure security. Nevertheless, it has been taken into account in this book that each country has its inherent unique dynamics and circumstances. As a final step, the energy and energy security policies of the Republic of Türkiye were evaluated in conjunction with the goal of Türkiye to become an energy actor.