The dependence on renewable energy to solve the major energy issues related to global warming and shortage of energy resources is increasing drastically. This has led to high level awareness of proper energy storage and management. In this regard, supercapacitors have evolved as an efficient energy storage solution and hence successfully employed in several applications. This is attributed to its high-power density, superior performance, and extended maintenance-free lifetime. Also, it is known for low equivalent series resistance, that means, only a small amount of energy is lost while its charging/ discharging even at high current. As a result, it has developed a lot of inquisitiveness among the research community of recent past for further exploration of different aspects of supercapacitors, ranging from material science, modeling and characterizations, engineering applications, and so forth. This review article aims at putting forth an exclusive study of their characterization of supercapacitor for different charging methods and applications. Further, the prime focus is given to the efficiency estimation of supercapacitors which is very essential as it denotes the amount of energy loss or the utilizable state of charge. The analysis has been carried out based on different charging methods and applications, which is essential for improving overall system reliability and performance. The purpose is to organize all important research carried out in this domain till date and to stimulate further insights for effective energy storage and management.