Actually, they can. A screen capable of 4K has roughly four times the resolution of a 1080p HD display. This means that there are more pixels per inch (PPI) of screen, allowing for better detailing. When you pair greater pixel density with the higher refresh rates 4K displays can achieve, you get smoother playback that's ideal for action movies, sports, and gaming. A refresh rate is the number of times your screen refreshes in a given second.As you can imagine, the faster the refresh rate is, the better quality your image will be.