The term Web Standard for the purposes of this site, means that the standard syntax of the feature works in all up-to-date browser software, without prefixes, and is safe for use in production of modern applications. Web technologies are evolutionary. Over the years they receive new features and do away with unnecessary features. When new features are introduced, it takes a long time for browser vendors to integrate the features into their software. Some browser vendors integrate new features into their software faster than others. CSS level 3 is still considered experimental since it is newly introduced. Authors should treat CSS3 features as experimental. You will see this type of information listed for every CSS property referenced on this site: CSS Level: 1, 2, 3 Web Standard: yes, yes, not yet That means that the property and all of its possible CSS level 1 and 2 features are considered a web standard, but not its new CSS level 3 features. Some of the new features it may possess given to it in CSS level 3, might not work in all up-to-date browser software yet. If a CSS level 3 property itself is not yet a web standard, authors are encouraged to apply vendor specific prefixes to those experimental properties in order to make them work in specific browsers. Authors could also implement fallback content when a new feature of CSS appears to not be working universally in all up-to-date browser software.
Browser PrefixesChrome and Safari browsers may require the -webkit- prefix. Firefox browser may require the -moz- prefix. Internet Explorer browser may require the -ms- prefix. Opera browser may require the -o- prefix. Example of applying the prefixes to new experimental CSS features:
-webkit-animtation: box-move 1.5s linear 0s; -moz-animtation: box-move 1.5s linear 0s; -ms-animtation: box-move 1.5s linear 0s; -o-animtation: box-move 1.5s linear 0s; animtation: box-move 1.5s linear 0s;The standard syntax version goes last after the prefixed lines.