You can also use more than 1 in the same document:
Code:
<head>
<title>Chapter-5.html</title>
<link href="../Styles/standard.css" rel="stylesheet" type="text/css" />
<link href="../Styles/template_5.css" rel="stylesheet" type="text/css" />
</head>
'standard' is the general' css
and template 5 is the additional styles needed for this document.
IIRC if a selector duplicates previously defined one (in standard), the last style found is used, so you could even override 'standard'