Flash: noun, light source that provides a brief, powerful burst of bright light timed in-concert with the camera to expose the sensor or film. Flash, also called strobes, is the standard artificial lighting for photography. The intense power and speed of flashes allows for maximum creative control in a wide-variety of lighting conditions.

LEDs: noun, continuous lights made with light-emitting diode technology for photo and video applications. LEDs use way less power, run cool, and can output in just about any color or color temp, but are much lower power compared to flash strobes, HMIs or tungsten hot lights. The Arri Skypanels and Kino Flo Celebs are the best ones.

HMI: noun, a continuous light from a hydrargyrum medium-arc iodide light source. HMIs are designed for video applications, but have became more common on photo shoots after the introduction of Arri M18. Praised for the daylight color temperature and a specular-hard-yet-soft quality of light. Popular for achieving a film-like look. They do require a ballast, wide apertures and higher ISOs.

Hot Lights: noun, continuous light sources that are tungsten or HMI technology. These lights give off excess amounts of heat and are hot to the touch. They can burn people and melt objects/start fires. Hence, the name “hot lights”. Handle with heat-resistant gloves and care.