The ability to increase energy efficiency and utilization rates while bridging the gap between energy demand and supply has led to a rise in the popularity of thermal energy storage (TES) systems in recent years, making them an attractive solution to the problems of environmental pollution and energy scarcity. As a subset of thermal energy storage, latent thermal storage systems are of particular importance due to the high latent heat storage (LHS) density and generally constant phase change temperature of phase change materials (PCMs) used as storage medium. Although organic PCMs have traditionally been the focus of PCM research, recently there has been a lot of interest in inorganic PCMs with wide phase transition temperature ranges. Because of their lower phase transition temperature, hydrated salts are increasingly replacing molten salts and metals in applications such as construction, solar water heating, textiles, etc. Inorganic salts, for instance, have exceptional qualities due to its great latent heat storage volume, whereas metals have exceptional properties for its very high thermal conduction. The aim of this analysis is to familiarize the reader with inorganic PCMs, to summarize recent research on them, to offer a quick explanation of their thermal characteristics, and to highlight their applications in heat exchangers and certain major systems.