Electrochemical capacitors (ECs) or Supercapacitors (SCs) are one of the growing efficient energy storage technologies due to their high power density, high charge/discharge rate and long cycling stability. To understand the fundamentals of ECs, we detailed the process behind charge storage, classification, as well as the various components of ECs and how they function. Transition metal compound-based materials (TMCs) are potential electrode materials for pseudocapacitors due to their increased electrochemical properties via redox processes. We presented the current advancements in transition metals oxides (TMOs), transition metal sulphides (TMSs) and transition metal nitrides (TMNs) as electrode materials with few illustrations. In order to witness the high performance, some possible strategies which can be effectively utilized like metal doping, formation of nanostructures, and composite formation are outlined. These approaches can improve the overall performance of SCs by overcoming limitations such as poor electrical conductivity, low energy density, and etc. Finally, a view on obstacles and future prospects for their efficient use in diverse applications is provided.