While HTML lets you do many things, Cascading Style Sheets (CSS) let you do even more. In particular, they can save you a great deal of work when you want to make changes to the appearance of a Web page or even an entire website. This first article in a series covering CSS will explain where the CSS specification comes from and show you just a few of the ways you can use CSS.
Learn CSS, part 1 - CSS Specifications and Implementations (Page 2 of 7 )
Let's talk a little bit about what's going on with CSS and who actually designs and implements it for us. The Web gets more complicated every day, so we needed a way to make web standards. What I mean by Web standards is that, when you write a piece of code in a certain markup language, it should function the same way on any operating system or browser. The W3C (World Wide Web Consortium) is an organization that defines those Web standards. Its member organizations include Microsoft, Oracle, Sun, Adobe, Google and many more. You can see the full list of members at this page: http://www.w3.org/Consortium/Member/List. The W3C Consortium defines how the technology should work, and in fact most of the technologies we work with are W3C standards such as HTML, XHTML, XML, XSLT and CSS (and many other technologies).
Within the W3C, there are working groups which are responsible for designing the technology. The working group of a given technology (like the CSS Working Group) produces documents called CSS specifications. These Specifications specify how the CSS Language should function. Note that the working group doesn't produce any software. In other words, the CSS Working Group doesn't implement the specifications; it just produces standard specifications, so when (for example) Microsoft creates a new version of its Internet Explorer, it decides which parts of the specifications it will implement (maybe it will implement all of the specifications, or only a few parts of them). This is a very important issue, and we will talk about it shortly, but for now you might want to know that the browser that is best at supporting CSS is Mozilla.
When the Specifications are complete (which means that the Specifications have been reviewed) it becomes Recommendation and this is a perfect expression, Recommendations, because as we have said that the W3C Consortium has no control over the various implementations of the Specifications it produces. There is another expression called Candidate Recommendation which the W3C call on the Specifications that being tested and reviewed and just before it becomes an Recommendation. CSS has 4 Specifications documents. CSS Level 1, CSS Level 2, CSS Level 2.1 and CSS 3. Each specifications is built on the previous one, right now the CSS Lever 2.1 is a Candidate Recommendation and CSS 3 is under development. I will focus on the CSS 2.1 Specifications and I will take a peek at CSS 3 when appropriate. Now let's take a look at the browsers we will use.