A New Theory Expands Einstein's General Relativity Theory to Include Both Electric Charge and Mass EntitiesEinstein's General Relativity Theory explains why two Mass Bodies Attract each other according to Newton's Gravitation Law: F = G⋅(m1⋅m2)/r2. The General Relativity Theory concluded that a Distortion of the Interwoven Space/Time Entity, caused by one Mass, guides all other Mass Bodies how to attract towards it. Interestingly, Coulomb's Law: F = Ke⋅(q1⋅q2)/r2, that defines the Attraction/Repulsion between two Electric Charges, has an identical structure to that of Newton's Gravitation Law's. So, it is reasonable to wonder if the origins of the Attraction/Repulsion between two Electric Charges are also similar. This question is this study's focus. A New Theory proposes an answer to this question.Mass and Electric Charge are fundamental entities of the natural matter. The nature of the entity of Mass Bodies and their interactions, was studied extensively by Newton's Theories and Einstein's Relativity Theories, while the nature and the characteristics of the Electric Charge Entity was limited to the study of Electric Fields and Electromagnetism, which was studied prominently by Maxwell [1]. However, fundamental questions such as “What is Basically the Nature of the Electric Charge Entity?”, or “How and Why do Electrically Charged Bodies Interact the Way They Do?”, were not yet answered. This article is a third of three articles that summarizes a broad research work intended to investigate and study these questions, investigating specifically the nature and characteristics of the Electric Charge Entity. The first two parts of this research, dealing with Electric Charge, Energy, and Space, were already concluded, and published in two articles [2], [3]. The present article provides a summation of the third part of the research that is focused on the origins of the Electrically Charged Bodies' interactions. As mentioned above, the Mass Entity was thoroughly studied, prominently by Newton and Einstein. So, the basic scientific knowledge relating to the question: "Why and How do Mass Objects Attract Each Other?" is answered through Newton's Universal Gravitation Law, and especially by Albert Einstein's General Relativity Theory. However, the same question related to the Electric Charge Entity: "Why and How Do Electrically Charged Bodies Attract or Repel Each Other?" was not answered yet. We do have knowledge about the force magnitude of attraction or repulsion between Electrically Charged Bodies through Coulomb's Law, but we still do not have any explanation to the question of: “Why and How Do Electrically Charged Bodies Impose Such a Force on Each Other?” Or: "What is the Origin of the Electric Coulomb Force?" This study's aim is to investigate these questions. Newton's Universal Gravitation Law defines the force by which two MassMoshe Segal