- Resolutions 

The amount of pixels viewed on the screen, 1920x1080 being HD 1080p.

- Aspect Ratio 

The ratio of the width to the height of an image or screen.

- Different Panel (LED, IPS & TN)

IPS has better viewing angles when compared to a TN panel.

IPS -

IPS technology is developed chiefly by LG Display, PLS technology by Samsung and AHVA by AUO.
The real selling point of these is their superior colour accuracy, consistency and viewing angles when compared to the other LCD technologies

TN - Elatively low manufacturing cost and a relatively high level of responsiveness; the pixels change their state quickly which helps make moving images appear smoother.

- Hertz

The amount of frames that can be displayed on the screen( 60hz, 120hz, 144hz, 240hz). TN Panels have the best viewing quality and can support the most amount of hertz. 

- CSGO Display Type TN

A game like CSGO would be best with a  TN display because the pixels update more frequently   and that helps the image looks smoother. In CSGO this would help you as player models would update faster giving you a better advantage in game as well as mouse movement being a lot smoother on the screen.

CSGO before the 15/9/15 update used to have box type hitboxes what made the game less competitive and fun for players. It meant that when players were sometimes aiming on the enemy  the game wouldn't register it as a hit. 

As shown in the picture below the hitboxes of the player is a good couple of cm to the left of the actual model. 

Another bug in CSGO was where players could see through smokes in the game and see players. Again this is a big problem in a competitive game as it gives the players an advantage. 

In CSGO there 2 ways to report a bug through email of valve and selecting what game you're having a problem with, then your email, the subject, and the message saying what bug you found maybe with screenshots etc. 

The second way to do it is through 3rd party sites about CSGO example reddit and hltv. Then creating a form/discussion about the bug/glitch. Then if it's a big problem in the game the community will get it to the top of reddit or hltv, then the game devs normally go through these type of sites to see what the community is saying.

Bug testing is a phase in production in the game making, where specific roles in the team will test the game. This includes playing the same level over and over again trying to find bugs and glitches in the game to make it as polished as possible. This is an important part of the development because it will deliver a more quality game and make it fun for players.