What is ntsc in the laptop display and how does it compare?

45% NTSC 144Hz display (with Ryzen 5 5600h)

72% NTSC 144Hz display (i5 10300h)

Is that a big difference and what does it make in practice?

Color quality
The more colors your panel can output, the more vivid the display will be. For laptops, the color rendering is measured in the sRGB color space. The best come to over 95%, some are even 100%. Some manufacturers also approach the special information in NTSC or Adobe RGB. A value of 72 percent NTSC roughly corresponds to an sRGB color space of 100%.

https://www.techoxid.de/das-richtige-notebookdisplay/