As the refresh rate of a screen increases, the amount of images shown also increases. This can make the picture shown on the screen clearer, avoiding motion blur. (Motion blur is when something moves very fast, and it looks blurry. If a screen can not show images fast enough to keep up with an object, motion blur might happen.) Many televisions and computer monitors run at 60 Hz. This is a very common refresh rate. Because 60 frames per second is a common frame rate, 60 Hz monitors can show most things very clearly. However, some people want to have a higher refresh rate, because they use things like video games or very high quality videos, which can have much higher frame rates. Many screens have 120 Hz, 144 Hz, or 240 Hz refresh rates for this reason.