What does media = screen Mean?

To support earlier browsers, you must stick to the css1 media descriptor screen and print. They are mutually exclusive. Therefore, when a page is generated for the screen display, the browser will ignore the print style sheet, and vice versa. Therefore, each style sheet must contain the same style selector, but there are different rule declarations to generate page styles for different output devices.

<Link rel = "stylesheet" type = "text/css" media = "screen" href = "liehuo_net.css"/>

Screen (default), submitted to the computer screen;
Print, output to the printer;
Projection, submitted to the projector;
Aural, speaker;
Braille, submitted to the convex-text tactile sensing device;
Tty, telex typewriter (using a fixed font );
TV, TV set;
All, all output devices