Explanation/Reference:
Explanation:
To apply the same style consistently throughout your Web site you should use external style sheet.
Cascading style sheets (CSS) are used so that the Web site authors can exercise greater control on the appearance and presentation of their Web pages. And also because they increase the ability to precisely point to the location and look of elements on a Web page and help in creating special effects.
Cascading Style Sheets have codes, which are interpreted and applied by the browser on to the Web pages and their elements.
There are three types of cascading style sheets.
External Style Sheets

Embedded Style Sheets

Inline Style Sheets

External Style Sheets are used whenever consistency in style is required throughout a Web site. A typical external style sheet uses a .css file extension, which can be edited using a text editor such as a Notepad.
Embedded Style Sheets are used for defining styles for an active page.
Inline Style Sheets are used for defining individual elements of a page.
Reference: TechNet, Contents: Microsoft Knowledgebase, February 2000 issue PSS ID Number: Q179628