Cascading Style Sheets (CSS) defines how HTML elements are to be displayed and in-short referred as CSS. It controls the appearance of multiple HTML pages by just including one single external style sheet. For storing external style sheets CSS files (“. css” extension) are used. CSS-based layouts along with table based layouts are used to manage the formatting of a web site. Cascading style sheets (CSS) make it easy to manage the formatting of a web site and it can be used to control the appearance of objects on a page or throughout a site.
It can be designed and redesigned, and can control the formatting of hundreds of pages, including fonts, link colors, margin settings and background images. It is widely supported by modern browsers and allows flexibility in positioning. CSS based layouts Keeps the HTML/text ratio at a low level thus decreasing load time and Allows the display of main content first while the graphics load afterwards. CSS also avoid accessibility issues raised by table cells and the content flows logically without disruption. The three ways by which style can be added in HTML document are:
1. External style sheet 2. Internal style sheet (inside the <head> tag) 3. Inline style (inside an HTML element) In terms of priority when HTML document displays, it first looks for Inline style, than for internal style sheet (inside the <head> tag) and at last include External style sheet which is CSS. External style sheet (CSS) enables developer to change the appearance and layout of all the pages in their WebPages by just editing one single CSS file. Internal (embedded) style sheets are useful for managing single HTML page in which it is included and inline style sheet are used for managing some special formatting within the webpage.
The Evolution of HTML Standards The evolution of HTML standards started from 1989, when Tim Berners-Lee invented the Web with HTML as its publishing language. In September 1991, Open discussion about HTML across the Internet begins. In 1992, HTML 1. 0 the first release of HTML to the world, was taken from Tim-Berners Lee original proposal. At this time not many people were involved in website creation and the language was very limited. In May 1994, HTML+ having some physical layout was shown at the first World Wide Web conference (W3C) that was held in Geneva. In July 1994, HTML specification for HTML 2. 0 was released.
It included everything from HTML 1. 0 and added a few new features and defined many core HTML features for the first time. It was HTML standard until January 1997. In March 1995, HTML 3. 0 published as an Internet Draft by a HTML working group, led by Dave Raggett. In 1996, HTML 3. 2 (wilbur) came after the end of the Browser Wars and became the official standard in January 1997. It had included the tags introduced by Netscape and Microsoft during Browser Wars. In December 1997, HTML 4. 0 (cougar) introduced with HTML’s new supporting presentational language, cascading style sheets and became the official standard in April 1998.
HTML 4. 0 was revised and corrected and later introduced as HTML 4. 01 in 1999. In January 2000, XHTML 1. 0, an XML version of HTML 4. 01, became joint standards along with HTML 4. 01. In XHTML 1. 0, there are not many new or deprecated tags and attributes but it was changed with a view of increased accessibility and functionality and a new set of coding rules. In 2001, XHTML 1. 1 with some modularization came. In 2002, XHTML 2. 0, which is more simplified and generalized standards, came into effect for WebPages. References: CSS Tutorial available at <http://www. w3schools.
com/css/css_intro. asp> accessed on 27 July 2007. Web Development Series: formatting content, January 4, 2007 retrieved on 27 July 2007 from <http://academictech. doit. wisc. edu/ORFI/wds/index. htm> Moller, A. & Schwartzbach, M. L. 2006. HTML and Web Pages: An Introduction to XML and Web Technologies, Addison-Wesley. Retrieved on 27 July 2007 from <http://www. brics. dk/ixwt/html. pdf> Shannon, R (n. d. ). The History of HTML Retrieved on 27 July 2007 from <http://www. yourhtmlsource. com/starthere/historyofhtml. html> http://www. w3. org/ accessed on 27 July 2007.