Hot Shoe describes the area of a camera where the flash piece is attached to the camera base. Shaped like a horse shoe, the hot shoe has two parallel rims under which the flash unit is slid to fix it to the camera. When the flash attachment is fixed, a metal piece on the underbelly of it connects to a similar metal piece on the camera. As your camera fires off a flash, an electrical current passes through the camera’s metal outlet to the flash unit.
More sophisticate (and, therefore, higher end) cameras contain more points of metal contact between the camera and the flash unit. This increased degree of communication helps a camera automatically switch its settings, as well as reduce the red-eye effect.
The hot shoe can be found on both digital and manual cameras. However, while a hot shoe on a camera can improve shots, a flash bracket that anchors a camera to a tripod provides more control for more particular photographers.