Cascading Style Sheets (CSS) is a style sheet language.
Styles define how to display HTML elements.
External Style Sheet can save lot of time and energy.
CSS helps Web developers create a uniform look across several pages of a Web site.
Once the style is defined in cascading style sheet, it can be used by any page that references the CSS file.
CSS defines HOW HTML elements are to be displayed.
Styles are normally saved in external .css files. External style sheets enable you to change the appearance and layout of all the pages in a Web site, just by editing one single file!.
Style sheet contain Property:Value.
eg:
color:red;
Property:value;