system
Given the following post, respond as if you're commenting on Reddit:
human
What happens when part of my monitor is black?

Lets say that I open up a terminal window on my computer. The terminal window has a black background. I understand that each colored pixel of my monitor is generated by red, green and blue light. When I view the black background of my terminal window on my monitor, does that mean that my monitor is "off" at those pixels?
gpt
There is a backlight behind your monitor's LCD screen that continuously emits white light; when a pixel is "off", it transmits all of the wavelengths in that light through the screen at that point, and you see a white pixel. When the computer asks a pixel to turn a certain color, the pixel blocks only the wavelengths of light that *are not* in that color (e.g., a pixel displays red by blocking all of the wavelengths of light but red). For black, the pixel blocks all of the light. Does that make sense?