Cascading Style Sheets
W3C has introduced CSS (Cascading Style Sheets) for presenting an HTML document. CSS functions as ‘style templates’, used to determine how elements in a browser. CSS is often applied as a separate file used to influence the design of the whole site.
Web developers should keep structure and presentation separate as much as possible. That is why it is strongly recommended to use CSS for the presentation site as much as possible. CSS should preferably be placed in linked external files. Web developers should also bear in mind that pages are to remain accessible if CSS is not supported.
Web developers should at least utilise the possibilities offered by CSS Level 1. Browser support for CSS Level 2 is middling, but there are several shortcomings as a result of which the threshold for beginners is usually very high. Familiarity and experience with these shortcomings are required before a web developer decides to set up a full CSS layout.