CSS, or Cascading Style Sheets, specifies the style of font and other features that are used within HTML documents. For instance, it is advisable to use a consistent set of fonts across your entire website, rather than varying them from page to page. You could include these style elements in every page you publish, or you can ensure all of your pages have the same look by creating a CSS file for your site. In the CSS, you specify the font for different styles of text, such as your headers and body text. Wherever you use a defined text element on your site, it will be referenced against the CSS file to ensure it always looks the same.