What Does Cascading Style Sheets Level 3 (CSS3) Mean?
Cascading Style Sheets Level 3 (CSS3) is the iteration of the CSS standard used in the styling and formatting of Web pages. CSS3 incorporates the CSS2 standard with some changes and improvements.
A key change is the division of standard into separate modules, which makes it easier to learn and understand. As of February 2014, the standard is still under development by the World Wide Web Consortium (W3C), but a number of the CSS3 properties have been implemented in the latest versions of some Web browsers.
Techopedia Explains Cascading Style Sheets Level 3 (CSS3)
CSS3 makes changes to how some visual elements are implemented and rendered by a browser. However, it is not a single hugely unwieldy specification, unlike CSS2. CSS3 is separated into separate modules to facilitate development. This means that the specification comes out in chunks, with more stable modules than others.
Some would be ready for recommendation, while others would be marked as under development drafts, the most recent of which were published as early as June 1999.
Some of the major modules of CSS3 are: