A klieg light is like a really big flashlight that people use when they want to make something extra bright. It's called a klieg light because a long time ago, when they first made these kinds of lights, they used a special kind of light bulb called a klieg bulb.
The light is usually high up and shines down on things like a stage or a movie set. It's a very powerful light, so it can make things look much brighter than they normally would. This is useful for people who make movies or put on shows because they want to make sure you can see everything that's happening.
Sometimes people use klieg lights to make things look more dramatic or exciting. For example, they might use a klieg light to shine on a singer as he or she finishes a big song. This can help create a really special moment.
Overall, a klieg light is a big, powerful flashlight that people use to make things look brighter and more exciting.