CSS Versions

Cascading Style Sheets, level 1 (CSS1) was came out of W3C as a recommendation in December 1996. This version describes the CSS language as well as a simple visual formatting model for all the HTML tags.


CSS2 was became a W3C recommendation in May 1998 and builds on CSS1. This version adds support for media-specific style sheets e.g. printers and aural devices, downloadable fonts, element positioning and tables.

CSS3 was became a W3C recommendation in June 1999 and builds on older versions CSS. it has divided into documentations is called as Modules and here each module having new extension features defined in CSS2.

CSS3 Modules

CSS3 Modules are having old CSS specifications as well as extension features.

Selectors
Box Model
Backgrounds and Borders
Image Values and Replaced Content
Text Effects
2D/3D Transformations
Animations
Multiple Column Layout
User Interface
 CSS Syntax

A CSS comprises of style rules that are interpreted by the browser and then applied to the corresponding elements in your document. A style rule is made of three parts −

·        Selector − A selector is an HTML tag at which a style will be applied. This could be any tag like <h1> or <table> etc.

·        Property - A property is a type of attribute of HTML tag. Put simply, all the HTML attributes are converted into CSS properties. They could becolor, border etc.

·        Value - Values are assigned to properties. For example, color property can have value either red or #F1F1F1 etc.