As the web evolved, this structural started evolving into a presentational language. Consequently, large parts of HTML 3.2 and HTML 4.0 are devoted to presentational elements. A FONT tag is of no use to a speech-synthesis browser, it has no way of knowing that the text is any different from any other text. If all the content of the page is in images, the page is not accessible and download times are lengthy, nor are the pages easy to update. Using tables for layout has been the only reasonable solution, but updating and debugging are difficult due to the excessive markup.
Structured markup is easier to maintain.
A style specification or style sheet is simple a collection of rules. Style sheets are a means for controlling the presentation of web pages, and keeps HTML to its original intent, as a structural language. Rich styling - allows for much richer styling that HTML allows. This will override the imported rule or external file. Compact File Size - by creating style sheets, you reduce the amount of markup in the file, thereby decreasing the file size and increasing the speed of download.