Summary about CSS Cascadong Style Sheets is a style sheet language used for describing the look and formatting of a document written in a markup language. While most often used to style web pages and interfaces written in HTML and in XHTML, the language can be applied to any kind of XML document, including plain XML, SVG and XUL. CSS is designed primarily to enable the separation of document presentation, including elements such as layout, colors, and fonts. This separation an improve content accessibility, provide more flexibility and control in the specification of presentation characteristics, enable multiple pages to share formatting, and reduce complexity and repetition in the structural content. CSS can also allow the same markup page to be presented in different rendering methods, such as on-screen, in print, by voice, and on Braille-based, tactile devices. It can also be used to allow the web page to display differently depending on the screen size or device on which it is being viewed. While the author of a document typically links that document to a CSS file, readers can use a different style sheet, perhaps one on their own computer, to override the one the author has specified. However, if the author or the reader did not link the document to a specific style sheet the default stle of the browser will be applied.