Quick question regarding LCD monitor

[Carfax]

My LCD monitor has different modes, such as picture, game, movie, user etc

Depending on the mode, the image quality is different.

Normally I have it on user, but I noticed that when I put it on movie mode, the colors in games look deeper and more vibrant. Also, shadows appear darker as well.

I'm just curious. What is the monitor doing when I choose movie mode?

[RADCOM]

Probably just increasing the contrast. Look at the monitor settings in each mode and compare.

[khamo]

Just changes in contrast, white balance and color saturation is different in different modes. You should be able to customize each depending on your taste.