The information here is out of date. But don't worry. If you've ever viewed the same Web page with a different computer, you may have noticed that the two computers displayed the page's text in different fonts. This is because browsers use fonts installed on their computers to display Web pages. This helps ensure that people everywhere can read Web pages no matter what computer, browser, or fonts they use.
Many email programs use fixed-width fonts as their default.
Proportional fonts are used to display most of the type on Web pages you visit. Monospaced fonts are used for text-input fields and certain kinds of preformatted type. The fonts that your browser uses depends upon your computer model, your operating system, and the fonts you've installed on your computer. You can change these default fonts to make pages easier to read or more attractive to you. If a Web page does not specify fonts, your browser will always use your default fonts.