A rechargeablelight( or flashlight)is a portable hand-held electric light. The source of the light is usually anincandescent light bulb(lamp) orlight-emitting diode(LED). A typical flashlight consists of the light source mounted in a reflector, a transparent cover (sometimes combined with alens) to protect the light source and reflector, abattery, and aswitch. These are supported and protected by a case.The invention of the dry cell and miniature incandescent electric lamps made the first battery-powered flashlights possible around 1899. Today, flashlights use mostly incandescent lamps or light-emitting diodes and run ondisposableorrechargeable batteries. Some are powered by the user turning a crank or shaking the lamp, and some have solar panels to recharge a battery.In addition to the general-purpose hand-held flashlight, many forms have been adapted for special uses. Head or helmet-mounted flashlights designed forminersandcampersleave the hands free. Some flashlights can be used underwater or in flammable atmospheres. Flashlights are used as a light source when in a place with no power or duringpower outages