Monitors are rated by their resolution, and by their Hertz. The resolution of a monitor is how many pixels it has, listed as the number of pixels across, then the number of pixels down. The Hertz is the speed with which the monitor refreshes.
There are a couple of common speeds for monitors, with two of the most popular being 60Hz and 144Hz.
A 60Hz monitor will refresh images at a speed of 60 images per second. Meanwhile a 144Hz monitor would refresh at a speed of 144 images per second.
Is More Always Better?
TV tends to be broadcast at 24-30FPS depending on the standard being used. Movies tend to be shown in 60FPS. Many old games aim for 30FPS, as about the level where the human eye starts to see fluid movement.

Some people may go so far as to claim that the human eye cannot detect the difference between faster frame rates, but that’s not strictly true.
Images that are shown at 144Hz will seem smoother and more fluid than ones that are shown at just 60Hz.
However, there are some downsides to high-Hz monitors. If you have a 60Hz monitor, then the monitor is showing 60 images per second. That effectively caps the framerate in games to about that level. Yes, your games might report that they’re showing faster framerate, but the monitor isn’t.
When you have a 144hz monitor, you can have higher framerates, which is great when the framerate is stable, but it becomes noticeable when the framerate dips. A stable framerate of 60fps looks great. A game running at 90fps dipping to 60fps is going to feel like it is experiencing game-breaking, crippling lag.
Gaming in 3D
While 3D gaming has fallen out of fashion somewhat, there are some classic titles that support it. Older devices such as Nvidia 3D vision relied on active shutters which would allow you to see one frame with one eye, and one frame with another. For these to work, you needed a monitor that had at least a rating of 120hz. On a 60Hz monitor, you would be limited to 30FPS, and the device would not work.
How Powerful is Your GPU?
Many 4K monitors are only 60Hz, but they are still high-quality monitors that produce clear displays. Remember that to ‘keep up’ with the Hz rating of the monitor the GPU needs to send frame data at the right speed. It takes more memory, and more processing power, to generate 120 or 144 frames at a given resolution than it does to generate just 60 at that resolution.

Of course, if you have an Nvidia 2080 or an equivalent ATI card you can use the latest, highest Hz monitors and get the full benefit out of them. If you’re using an older card, then you might be limited to a 1920×1080 display simply because of the lower memory capabilities of the card.
Remember that the Hz rating of a monitor is just one feature. Look for G-Sync, color depth, pixel density and the ‘black to black’ time, dead pixel warranties, and other features as well. Make sure that your graphics card and processor are up to the task. There’s no need to buy a 144Hz monitor if you are relying on onboard graphics.
In contrast, if you’re aiming to play the latest action RPGs or shooters, then it might well be worth investing in a 144Hz monitor just for the improved response time. Of course, if those types of games are your thing, you will want a good wired mouse and a mechanical keyboard with a soft response too.