Definition: An external flash is a piece of add-on equipment that creates an artificial source of intense light that can be added to photos shot with a digital camera. The external flash unit is not permanently attached to the camera.
With beginner-level digital cameras, flash units are built into the camera, and they usually fire automatically whenever the camera needs additional light. Digital SLR cameras most commonly make use of external flash units.
The external flash fits onto the camera through a hot shoe, which is a slot that usually sits atop the camera. The hot shoe allows the camera to sync with the flash. An external flash unit usually contains batteries separate from the camera.
Flash can refer both to the flash of light that occurs when the flash fires, as well as the actual flash unit that creates the light.
Also Known As: flash
