In this paper, a holistic review of the energy Internet evolution in terms of the architecture, types of ERs, and the benefits and challenges of its implementation is presented. An exhaustive summary of the designs and architectures of the different types of ERs is also presented. Energy Internet, as the product of the deep integration of energy system and Internet technology, can become a possible way to approach the "energy impossible triangle" in the process of energy transformation. It improves a reliability of the system, and provides an increased utilization of energy resources by integrating the smart grid with the. Then, we propose a new universal definition of the EI by bringing together the various existing definitions and concepts in light of the upcoming smart grid. We also pinpoint the fundamental technologies responsible for ITM University Gwalior, India. coordinating and. Part of the book series: Lecture Notes in Civil Engineering ( (LNCE,volume 292)) China clearly pointed out in the “14th Five-Year Plan” that “accelerating the energy revolution, building a clean, low-carbon, safe and efficient energy system, and enhance the capability of ensure energy supply.