A hot shoe is a mounting point on the top of a camera to attach a flash unit and other compatible accessories. It takes the form of an angled metal bracket surrounding a metal contact point which completes an electrical connection between camera and accessory for standard, brand-independent flash synchronization.
Canon EOS 350D Hot shoe
Proprietary hot shoe used by Minolta and older Sony cameras (Konica Minolta Maxxum 7D)
Minolta SRT101 accessory shoe without electrical function
A flash is a device used in photography that produces a brief burst of light at a color temperature of about 5,500 K to help illuminate a scene. A major purpose of a flash is to illuminate a dark scene. Other uses are capturing quickly moving objects or changing the quality of light. Flash refers either to the flash of light itself or to the electronic flash unit discharging the light. Most current flash units are electronic, having evolved from single-use flashbulbs and flammable powders. Modern cameras often activate flash units automatically.
The high-speed wing action of a hummingbird hawk-moth is frozen by flash. The flash has given the foreground more illumination than the background. See Inverse-square law.
Demonstration of a magnesium flash powder lamp from 1909
Vintage AHA smokeless flash powder lamp kit, Germany
Ernst Leitz Wetzlar flash from 1950s