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Instruction Sheet

Thursday, July 15th, 2010

Instruction Sheet

The Low Down On Cascading Style Sheets

CSS has been around for more than 10 years already beginning in its development in 1997 but it seems it has been in the public consciousness for only a relatively short time. The reason for this is because it wasn't until the year 2000 that many web browsers began using the capabilities of CSS beyond its more basic color and font characteristics. Of course things are way different now and virtually all modern day browsers feature support for all CSS Level 1 aspects, many aspects of CSS Level 2 and some web browsers have even gone beyond that to support some of the capabilities of CSS Level 3.

Indeed, it is rarely that you find a web site nowadays that does not utilize some form of CSS in their design and development. For better or worse, web sites that rely solely on HTML are quickly going the way of the dinosaur. May industry pundits as well as end users have even gone so far as to consider a thorough knowledge of CSS as being far more necessary than a thorough knowledge of HTML. While in truth they are both equally important and will continue to be an important facet of the web for many years to come, there is no denying the widespread impact that CSS has brought upon the World Wide Web.

CSS was originally developed as a means by which web developers could define both the look and the feel of their web pages. With its inception, web designers were now able to treat content and design as two separate entities, thereby allowing HTML to function more in accord with its intended purpose, which was to focus on the markup of a particular web site's content and leaving the responsibility of the design and layout to CSS.

The term CSS itself is an abbreviation for Cascading Style Sheet. The style sheet in this particular instance refers to the document itself. The concept of style sheets itself is nothing new; designers have used them in their documents for many years. Strictly speaking, style sheets are the set of technical specifications that govern a particular layout, whether it is online or on print. The purpose of these of course is to ensure that any subsequent designs will conform to the predetermined specifications upon printing.

This concept can be translated easily enough to the World Wide Web only in this particular case, Cascading Style Sheets not only determine the technical specifications of a particular document on the web but also has the added function of communicating to the viewing vehicle (in this case the web browser that the end user is using to surf the Internet) exactly how the document that is being viewed is to be rendered.

One of the most important things to remember in all of this is the key word Cascade. Much like a stream of water running of a cliff or elevated area comes into direct contact with the rocks and soil that line the full course of the incline, yet is ultimately only affected in terms of its final destination by the land elements at the end of the slope, Cascading Style Sheets by their very nature flows or cascades through any number of separate style sheets. To follow the stream of water analogy even further, the appearance of a particular web site is ultimately dependent upon the user agent style sheet, which in many cases is the default style that the Web browser will utilize in the task of displaying a particular web page in the absence of any other set of instructions.

Of course more often than not, a web designer will probably provide any number of his own instructions that are embedded in the web page in question. The Cascading Style Sheet in this particular scenario will be tasked with dictating to the web browser which particular set of instructions will have top priority. The most commonly seen usage of this is in the fonts that are used for a web site. Even if your web browser is set to display web pages in a specific font and type size, say Arial narrow 10 points, the font size and family that is specified in the Cascading Style Sheet will take precedence overriding the default values that have been set in your browser.

Cascading Style Sheet go far beyond font specifications however into the areas of XHTML and XML markup. This means that Cascading Style Sheets could be used to define the look of any XHTML and XML markup that you use in your web site.

Clearly Cascading Style Sheets are one of the most powerful tools that any web designer can have in his or her arsenal and they can have a tremendous impact on the whole look and feel of a web site. If you are at all interested in becoming a professional web designer, a thorough knowledge of Cascading Style Sheets is crucial.

About the Author

Mikhail Tuknov is a
search engine optimization specialist
providing web site search engine optimization (SEO), pay per click (PPC) management and web analytics services.