Front-end development is the conversion of the approved graphic design into a code that web browsers can understand. This process should be divided into three parts: information, presentation and behaviour. This is based on the principle of the “Separation of concerns” which dictates that these parts be independent layers, each enhancing the layer before it, to ensure compatibility and flexibility in the future.
HTML = Information
Based on this principle, intraspin.com uses HTML purely to mark-up information; for example, as a header, paragraph or list item. The quality of your HTML has a significant impact on your rankings in search engines and on your conformance to accessibility legislation.
CSS = Presentation
CSS is then the language used to apply presentation instructions such as colour, background imagery, typefaces, spacing and layout to HTML. The key success criterion for CSS is that the site look the same across different browsers and platforms, given that each interprets CSS in slightly different ways..