Gaming monitors are optimised to allow for the best user experience when playing games on a PC. They will allow for a greater level of immersion in the game, making for more all-around enjoyment. It is also important to use the correct equipment so that you don’t injure yourself from sitting incorrectly or looking at the screen incorrectly.
This first thing to think about is pixels. The more pixels the better, right? Not quite. If you have more pixels, which will make the games look more realistic, you will need more power. A 4k monitor may look amazing but it will probably be a little slower on frames per second. QHD is a really good compromise.
Also, consider the panel tech for the best results. Twisted Nematic screens will fastest, providing the greatest level of accuracy. An IPS or VA display comes highly recommended for a PC that is used for gaming.