Web style sheets are a form of separation of presentation and content for web design in which the markup (i.e., HTML or XHTML) of a webpage contains the page’s semantic content and structure, but does not define its visual layout (style). Instead, the style is defined in an external stylesheet file using a style sheet language such as CSS or XSL. This design approach is identified as a “separation” because it largely supersedes the antecedent methodology in which a page’s markup defined both style and structure. The philosophy underlying this methodology is a specific case of separation of concerns.
* Style sheets (January 2, 2010) from Wikipedia: The free encyclopedia. Retrieved January 13, 2010 from: http://en.wikipedia.org/wiki/Style_sheet_(web_development)
* Hojas de estilo (November 16, 2009) from Wikipedia: La enciclopedia libre. Retrieved January 13, 2010 from: http://es.wikipedia.org/wiki/Hojas_de_estilo
