Internet Explorer: Understanding the Compatibility View List

In recent versions, Windows Internet Explorer has dramatically improved support for established and emerging industry standards, such as HTML5, Cascading Style Sheets, Level 3 (CSS3), and Scalable Vector Graphics (SVG). By default, Internet Explorer properly displays webpages designed to support these standards. Because some of these standards are still evolving, older websites may not fully support them. In addition, later versions of certain standards specify different behaviors than earlier versions of the same standard.