Energy storage devices can help electrical networks operate more efficiently whenever there occur imbalances between supply and demand. Enhancing the quality and dependability of electrical networks is another significant function of them. To large extent the issue of supply intermittency has reduced due to the use of energy storage devices. Flywheels are perfect for short-duration energy buffering and frequency regulation in contemporary grids because they perform well in applications that demand quick reaction times, high power output, and a long lifespan. They can quickly release excess energy when needed, stabilizing electrical grids, increasing the efficiency of machinery, and even helping spacecraft maneuver. Their distinct set of advantages, including as their high efficiency and environmental friendliness, ensure their significance in the changing field of energy management and mechanical systems, even in the face of obstacles like initial cost and competition from other storage technologies. This paper differs from prior assessments in that it gives a critical assessment of Fly wheel energy key components along with applications. In addition, prior judgments in this fast-moving sector have not been taken into account in the most recent research. The flywheel and its primary parts, the main uses of FESS, and the leading market participants have all been thoroughly investigated for usage in flywheel storage systems. Suggestions for more research are included in the paper’s conclusion.