Sounds like a its an older cheap TN monitor. They have truly terrible viewing angles. Sit back further from the screen and try to be a spot on in front of it as possible. By which i mean don't be looking down or up at it or from side to side, be dead straight on.
FYI LED and LCD are the same. LED was used as marketing to refer to the type of backlight used when it was new. Older LCD's used CCFL backlights, then they introduced LED ones. Nowadays all LCD use LED, so all LCD monitors and TV technically are LED. LED refers to the backlight though, they are still LCD displays.
The difference between displays is the panel type ..or LCD type. you have 3. TN , VA, and IPS.