Battery technologies are well established and widely used technology but they offer several disadvantages like weight, volume, large internal resistance, poor power density, poor transient response. On the other hand, due to advancement in the material and other technology, Supercapacitor or Ultracapacitors or Electrostatic Double Layer Capacitor (EDLC) are a most promising energy storage device. They offer a greater transient response, power density, low weight, low volume and low internal resistance which make them suitable for several applications. This paper summarizes recent research and development in the field of supercapacitor technology. This paper gives a brief insight into the design, characteristics and applications of the supercapacitor.