What's the difference between a flash and a constant light? Why not take constant photography?

I don't think I've ever heard of the word always-on light. But I know what you mean. That kind of thing is usually called a photographic lamp. What's the difference between flash and flash? As the name implies, the flash only flashes at the moment of taking a picture, while the photographic lamp can emit light continuously. From the effect point of view, photographic lights are usually better than flash lights, so professional studios generally use this. When shooting video, the flash is completely useless. You must use a photographic light. However, photographic lamps are bulky and troublesome to use. Basically, the venue needs to be arranged in advance. The flash is small and portable, and it also looks low-key when not shooting. Therefore, news photographers and amateur photographers usually use flash.