A review to understand what superconductivity is through its new redefinition and a path to establish its complete theory

Currently, the theory of superconductivity has been the subject of conversation and controversy in prestigious universities, large laboratories and companies involved in technology and scientific innovation. This interest is largely motivated by the possibility of constructing an experimental setup that exhibits its transition temperature corresponding to that of the Earth's ambient temperature and pressure. In this way, this new technology could replace many of the electronic components in use in civilization, reduce their cost-benefit ratio and become more efficient, as well as having many other scientific uses. For these reasons, in this article, this scientific researcher intends to show the new trends in the theory and experiment of superconductivity at the beginning of the 21st century, through an original summary about its developments and experimental advances. Furthermore, originally and in conclusion, propose a simple theoretical path for constructing a phenomenological theory, which could explain almost all or all experimental results and predict others. In this sense, a broad and new definition of superconductivity may be necessary, but one that does not reject its definition initiated with the experimental studies of Heilke Kamerlingh Onnes, et al.