CSS3 has received an incredible amount of coverage across the web, quickly transforming it into one of the industry's most frequently used buzzwords, but it's soon to be eclipsed and outdated by CSS4, right? Wrong!
In contrast to the preceding versions of CSS (1 and 2.1), CSS3 is not one giant specification that will eventually progress to CSS4 and beyond. Instead, the decision was made to modularize the entire specification, resulting in a comprehensive collection of various modules that all fall within the bracket of CSS3. Each of these modules is now free to progress independently at its own pace, without the possibility of being held back by other features.
The modules that simply further develop features from CSS 1 and CSS 2.1 are known as Level 3 modules, whereas brand new features and concepts form Level 1 modules. They will eventually progress to Level 4 and ...