External style sheet
From Wiki @ Karl Jones dot com
An external style sheet is a text file containing CSS rules.
External style sheet files usually have the .css file extension.
Example
A typical example:
<head> <link rel="stylesheet" type="text/css" href="sitename.css"> </head>
The above example is named "sitename.css", where "sitename" is the name of the website.
It is also common to name external style sheets after their function, for example "holiday.css" for styles which only apply during a holiday season.
