Why Stylesheets Are Important
CSS – cascading style sheet – is a fairly new method of designing web pages, one that separates the presentation from the content. The main reason style sheets are important is because they allow you to design all the pages of your website with one file rather than use HTML to design every single web page and all the elements on each page. With CSS you can set the design elements one time and apply them to all of your pages by calling the stylesheet forward at the appropriate time.
Web design is no easy task any way you look at it. But HTML has its limitations. With CSS you can overcome those limitations and design your entire website from one document.
Stylesheets operate on classes, the essential element of web design with CSS. Every element on a web page can be assigned a class and you can design a unique look for every web page on your website by using one stylesheet. All you do is assign each web page element a class as defined by the stylesheet.
There are many advantages to doing it this way, but suffice it to say that a website designed with stylesheets is much more flexible than one that isn’t.