MXene derivatives and composites are becoming fresh and promising two-dimensional (2D) materials because of their unique properties, performance, and multifunctionalities. This review covers the general aspects of MXenes (family of 2D transition metal carbides, nitrides, and carbonitrides), their MAX phase (a diverse class of nanolaminate materials with intriguing properties that have received incredible global research attention because they bridge the divide separating metals and ceramics.) precursors, dissimilarities and similarities between MAX phases and MXenes, and special properties of both materials. The important focuses are made on the methods of MXene synthesis and their stability and conductivity, as well as on synthesizing new MXene composites with desired characteristics. The impacts of MXenes in energy storage systems, especially supercapacitors, are discussed based on the high specific surface area, tunable porosity, and optimized inter-layer spacing. Here, various aspects of MXene materials, including properties, synthesis, and applications, have been discussed to highlight their importance for the development of energy storage systems and material science research.