CSS or cascading style sheets are used to create a set of styles that can be applied to your fonts, tables and most other attributes of your web page. These styles allow you to create a much cleaner, faster web page that search engines love and also makes life much easier on the designer when global changes to these styles need to be applied. It is also always critical to always keep in mind your target audience and the average Internet connection speed these users have. By using styles sheets to their full advantage, you can help keep your web page size down to a minimum.
Another good practice when designing web pages using CSS is to make sure your web page conforms to W3 standards for both HTML and CSS. This is critical in ensuring your website works across all platforms and browsers and also helps to ensure ALL search engine spiders can index your site easily and effectively. There really is nothing worse then directing a few hundred hits per day in search engine traffic and having 50% of those people unable to view your website because of poor coding, corrupted style sheets or broken links. Always test your web site and have a friend navigate through your website both on a MAC and PC to ensure there are in fact no broken links and all pages are easily accessible and error free.
The power of cascading style sheets is incredible. The above example only scratches the surface of how much you can do for your page in terms of accessibility, functionality, speed and clean html. You can adjust your scrollbar, background image, and even the padding of your tables all in your style sheet. The only key is that you create an external css and link it from the web page using those styles file (<link href="your-style.css" rel="stylesheet" type="text/css">). This way, you don't add any cumbersome code on your page that will risk confusing the search engine spiders and use CSS to its full advantage.
By adjusting all these attributes in an externally linked css file, you are keeping your web page small in physical size along with ensuring good clean html code which as we have mentioned above, search engine spiders love! As well, css makes life MUCH easier on the web designer when future updates need to be made. It is far more efficient to manage a website using cascading style sheets then one that contains good old font tags.