Some newer CRTs have flattened, squared-off screens that reduce glare. The number of picture elements, or pixels, that make up the image. More pixels mean finer detail. Most monitors can display several resolutions, generally ranging from 640x480 to 1,600x1,200 depending on the monitor and video card. The higher the resolution, the smaller the type and images, so more content fits on the screen.
Bigger screens can handle higher resolutions and display more information.
The number of times per second a screen is redrawn. The picture tube of a CRT demands that the image be redrawn many times a second. That can create flicker, which may cause eyestrain. The spacing between pixels. In general, lower numbers are better, producing finer detail and crisper images.