Stylesheet language is a computer language used to describe the presentation of structured documents. One modern style sheet language with widespread use is CSS (Cascading Style Sheets), which is used to style documents written in HTML, XHTML and other markup languages.
Style Sheets allow you to control the rendering — e.g. fonts, colors, leading, margins, typefaces, and other aspects of style — of a Web document without compromising its structure. Cascading Style Sheets (CSS) are a simple style sheet mechanism that allows authors and readers to attach style to Web pages. It uses common desktop publishing terminology which should make it easy for professional as well as untrained designers to make use of its features. Visual design issues, such as page layout, can thus be addressed separately from the Web page logical structure.
One of the main purposes of CSS is to separate the content from the document's structure. CSS is used to style the content of the document while HTML/XHTML/XML is used to build the structure. That way, once the document is "built", any changes to the look of the page can be made in the style sheets. The changes are made once and then take effect throughout the entire site. This makes the site much easier to maintain and, if necessary, change a small part of it or its entire format.
The concept of style sheets is actually quite simple. You take an element (h1, ul, img), apply attributes to it in the style sheet, and then just use the element in the HTML document. All of its formatting and other aspects are detailed in the style sheet.
However, it's not all that easy though. Its when we get into layouts, floats, margins, and other different formatting techniques that CSS begins to get a little complicated. But that's where we come in.
