After the formulations of Newton's and Maxwell's theories, it seemed that nothing else could scratch the path taken in the Physical description of natural phenomena. The principle of causality well described electromagnetic phenomena and the motion of celestial bodies in the sign of determinism. With the formulation of the Theory of Relativity Einstein continues a path of describing phenomena in motion even at speeds comparable to those of light. The change began with the deepening and studies at the atomic level where, Planck, Bohr, Einstein, abandoned the concept of continuity in favor of introducing the quantization of matter, while continuing, however, to interpret phenomena always with a classical foundation. It will take the input of the young Heinsenberg and Schoidenger to finally abandon the classical interpretation in the face of the mind-blowing new quantum interpretation. The subsequent formalization of quantum mechanics based on noncommutative algebra introduced by the young Dirac continues the path toward the ultimate use of quantum theory in the microscopic world. With quantum physics, a whole new way of behavior of matter and light is discovered in the realm of the microcosm. Grammatically, it would suffice to reverse a consonant and a vowel: moving from causality to casuality . An atom no longer consists of electrons orbiting like planets, no longer possessing a definite trajectory with certain values of velocity and position. Quantum physics describes the microcosm by preferring an evolution of nature toward disorder and uncertainty, rather than the determinism established by cause-and-effect, dominant in classical physics. Particles can transmit instantaneous information to each other, beyond the limit of the speed of light imposed by Einstein with the formulation of the Theory of Special Relativity. Understanding the behavior of matter at the atomic level will lead you to important reflections, and to think that nothing around us can be interpreted with deterministic rationality alone anymore. Hundreds of books can be found to understand the fabulous world of quantum physics, but most of the time they are either too popular in nature or are treated at the university level. With the present exposition, however, I have tried to cover the topics so that the concepts are mainly understood, but without neglecting the rigorous mathematical formulas and demonstrations, with sufficient language to be interpreted with mathematical and physical skills learned in a high school. The present text does not claim the prerogative of being exhaustive in the interpretation of quantum theory, but it is certainly useful for acquiring notions in order to be able to understand in a scientific view the texts on the market of a popular nature on the subject and in any case create excellent prerequisites for future in-depth studies of a university nature. I would like to thank all those who have been close to me during the writing of this treatise, and with the hope that I have set up the work in such a way that it will be useful to all those who approach the study of the fascinating world of Quantum Physics, I am grateful in advance to those who would like to propose improvements or any suggestions