ystems, such as social, biological, mental and other, are not yet developed. Any objects represent the systems, therefore interactions between them are interactions between the systems. But systems are formed at the expense of interaction between their elements and formations of inter-element relations between them. In the process of interaction between the systems intersystem relations are established. Any action, including interaction, needs energy. Therefore, when establishing relations/links/the energy is being "input". Consequently, as interaction between the elements of the system or different systems is the relation/link between them, the latter is the energy-related concept. In other words, when creating a system from elements and its restructuring from simple into complex, the energy is spent for the establishment of new relations/links/connections between the elements. When the system is destructed the links between the elements collapse and energy is released. Systems are conserved at the expense of energy of relations/links between its elements. It is the internal energy of a system. When these relations/links are destructed the energy is released, but the system itself as an object disappears. Consequently, the internal energy of a system is the energy of relations/link between the elements of the system. In endothermic reactions the energy used for the establishment of connections/links/relations comes to the system from the outside. In exothermic reactions internal energy of the system is released at the expense of rupture of these connections between its internal own elements which already existed prior to the moment when reaction occurred. But when the connection is already formed, by virtue of conservation law its energy is not changed any more, if no influence is exerted upon the system. For example, in establishing of connections/links between the two nuclei of deuterium (2D2) the nucleus 1Не4 is formed and the energy is released (for the purpose of simplicity details are omitted, for example, reaction proton-proton). And the 1Не4 nucleus mass becomes slightly less than the sum of masses of two deuterium nuclei by the value multiple of the energy released, in accordance with the physical expression of the conservation law. Thus, in process of merge of deuterium nuclei part of their intra-nuclear bonds collapses and it is for this reason that the merge of these nuclei becomes possible. The energy of connection between the elements of deuterium nuclei is much stronger than that of the bond between the two deuterium nuclei. Therefore, when part of connections between elements of deuterium nuclei is destructed the energy is released, part of it being used for thermonuclear synthesis, i.e. the establishment of connection/bond between the two deuterium nuclei (extra-nuclear connection/bond in respect to deuterium nuclei), while other part is released outside helium nucleus. But our World is tamped not only with ...