CSS

There are a number of advantages to using CSS.

It allows you to separate the design from the content of the webpage, which allows you to create much cleaner websites. You can use it to control more than one design element at once, so you can say that all the headings are a certain colour and font, but if you want to change that later on, all you have to do is change the code in the CSS and it will change all the other pages controlled by that style sheet.

CSS also allows the designer to implement more than one page design for a website with the use of exteranal style sheets. So you could have the one website, with the same content, but with completely different designs, you can also allow the user to change the style sheet.

It also useful with accessibility, as the CSS is different from the actual content of the webpage, it makes it easier for accessibility programs, such as readers, to view the webpage.