The @media rule allows different style rules for different media in the same style sheet.
The style in this example tells the browser to display a 14 pixels Verdana font on the screen. However, if the page is printed, the text will be in 20 pixels Verdana font, and in a red color.
See it yourself ! Print this page (or open Print Preview), and you will see that the text will be displayed in a larger font size, and in red color.