Some CSS properties are only designed for a certain media. For example the
"voice-family" property is designed for aural user agents. Some other
properties can be used for different media types. For example, the
"font-size" property can be used for both screen and print media, but
perhaps with different values. A document usually needs a larger font-size on a
screen than on paper, and sans-serif fonts are easier to read on the screen, while
serif fonts are easier to read on paper.