Native resolution

Native resolution is the Maximum and the best resolution supported by the entire-display

And Native resolution is only used in LCD displays and OLED and even All Flat-panel displays

Since the CRTs doesn't have any native resolution, So ,There are many people uses the CRTs because they supports a lot of resolutions.

Why CRTs doesn't have Native resolution?

The CRT (Short for Cathode-ray tube) is a Vacuum tube which contains one or more electron guns, Which lights the phosphor , When it's struck by electrons.

Most and modern color CRTs Uses 3-Electron guns to create all the colors you see on your screen

Anyway,The 3-electron guns uses the Magnets to beam the electrons , so they can sweep faster across the shadow mask and the phosphors and create the pictures you see on a CRT monitor.

That actually happens so quickly, depending on higher-refresh rates (60Hz or more)

How many times they scan the entire screen,are described by the Hertz of the refresh-rate. Keep in your mind, That 60Hz means "The electron guns , Sweep across the entire screen seixty(60) times per second

and the white color is created by "Three primary colors" and they are "Red and green and blue"

While all Mono-chrome CRT's doesn't have Maximum resolution, but All color-CRT's have Maximum resolution supported by the shadow-mask , Less Pixel pitch , means more Maximum supported resolutions by the CRT

-Insert PlayZ.

This one is from Wikipedia, Not from me ,So I hopefully that it helps you.