Hz is an acronym of hertz, which is the unit of frequency. One hertz is equal to one cycle per second.
In the context of display, it is how many times a display can redraw the images in a second and that is we call refresh rate.
Refresh rates are an aspect of the display. The higher the refresh rates means the higher the number of times a display can redraw or update the images sent by the GPU and CPU.
So 90Hz or 120Hz refresh rate display means the display can update the 90 or 120 images in a second sent by the GPU and CPU in form of frames.
The higher refresh rates signify the images you see gets updated more quickly than in the comparatively lesser refresh rates display, which would ultimately give you better viewing experience especially while gaming.
Understand the entire process
A frame is still image and a video is formed by combining still images in a sequence to achieve the illusion of natural motion.
Frame rate is defined as the number of images shown in a second and it is denoted by FPS (Frames per second).
Now to produce an image or frame, the Central processing unit (CPU) and Graphics processing unit (GPU) works together. CPU takes the digital signals meant for video from whatever source and transforms into a set of images or frames to be displayed.
It determines the actions of the AI, the physics, positions, and textures of the objects in the scene to produce an image.
Then GPU cuts this image into pixels at the resolution you set and sends this information to the display.
Eventually, the job of the refresh rate of a display comes in, which only updates the images on the screen and the higher the refresh rate the faster the images or frames will get updated giving you better viewing experience.does higher refresh rate display really matter to a normal user?
Yes, because the movies on Netflix and Amazon Prime and the videos we see on Youtube primarily and elsewhere, which are being shot at 24 or 25 FPS, would look a lot more fluid on a 90Hz refresh rate display than in 60Hz or 30Hz display as you will now be able to see the interim frames in the animation that would otherwise be lost.
Like in desktop computer monitors, even a smartphone with 90Hz and 120Hz refresh rate display is really good for gaming because now the GPU of the flagship Snapdragon 855 and 855 plus can render 60fps.
And that isAnd that is how Asus ROG Phone II /One Plus 8 Pro and many more with 120Hz refresh rate display is very good for gaming and that gives the gamers a far more immersive gaming experience than with a 60Hz display or even 90Hz display.
But FPS, as of now, by the flagship chipset makers, is limited to 60FPS. Maybe with Snapdragon 865 we will see the GPU that can able to deliver more FPS, which would be leveraged by higher refresh rates of the display and that would be fantastic for gamers. Because for them every move and every single frame counts to have an immersive experience.