Cascading Style Sheets are a big breakthrough in Web design because they allow developers to control the style and layout of multiple Web pages all at once. Before Cascading Style Sheets, changing an element that appeared on many pages required changing it on each individual page. Cascading Style Sheets work just like a template, allowing Web developers to define a style for an HTML element and then apply it to as many Web pages as they'd like. With CSS, when you want to make a change, you simply change the style, and that element is updated automatically wherever it appears within the site. Both Navigator 4.0 and Internet Explorer 4.0 support Cascading Style Sheets. If you needed any more proof of the problem-solving nature of CSS, the World Wide Web Consortium (W3C) has recommended Cascading Style Sheets (level 1) as an industry standard.