An Introduction to CSS

There has been a lot of talk about Cascading Style Sheets. You may not know exactly what they are. I wrote this article to explain what CSS does, why it is needed and how it does it.

The web is changing and developing all the time. CSS is one, coupled with DHTML, XML, and a whole host of other languages, that will try to tackle and solve some of the problems that HTML has.

One of the problems of HTML was that everything was lumped together. HTML was intended to be a language that marked bits of text as headings, others as emphasized (important text), or otherwise. This should have been used to give the documents on the web structure, search engines could have make words in headings more important than words in paragraphs, and bold text more important the nomal unformatted text. This however, did not work. People started to use HTML to make the text into different styles. For example some text may have been made bold to make it show up against the background colour. This meant that the documents lost their structure. CSS is a seperate language from HTML. Style and Structure can be seperated. This means that you can have a document with the structural HTML in place, giving importance to keywords in the document, whilst the CSS takes care of the appearance of the page on the screen, making text bolder, larger or smaller without affecting the structure. This means search engines will be able to index content better, one of the problems XML is also tackling. This means more efficient retreval of information.

Another problem of HTML was that the <FONT> tag was overused. Formatting happened on the page mixed in with the content. This made the file sizes quite large. With CSS you can group all your formatting defenitions for pages in your site into one file. Every page on your site draws its formatting information from the file, reducing the file download time of the HTML page, and increasing the overall download time of your site. This is because the CSS file is only downloaded once, stored in the cache (or Temporary Internet Files) on the users PC, then can be used by HTML files download from the site. As faster site is easier to use.

CSS will have many benefits in the future. I suggest that after learning HTML you take a look at CSS. I am going to write a few more CSS tutorials covering all you need to know.

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