In straight HTML, if you want to go up one level from a sub-folder, you use 2 dots slash ../doc.html. Get confused when seeing 1 dot slash ./doc.html or no dot slash /doc.html (as shown below). Does ths have to do with .ASP or .PHP?

Can you define/explain such usage?

Code:
<link rel="icon" href="/images/display/buttons/favicon.ico" type="image/x-icon" /> 
<link rel="shortcut icon" href="/images/display/buttons/favicon.ico" type="image/x-icon" /> 
<link type="text/css" href="/styles.css" rel="StyleSheet" />
<link type="text/css" href="/lightbox.css" rel="StyleSheet" />
<!--[if lt IE 7]>
    <script type="text/javascript" src="/dssleight.js"></script> <![endif]-->
<script type="text/javascript" src="/wom.js"></script>
<script type="text/javascript" src="/print.js"></script>
<script type="text/javascript" src="/4218.js"></script>
        <form name="searchForm" id="searchForm" action="/search.asp" method="get">
 ...
            <a href="javascript:document.searchForm.submit();"><img src="/images/display/buttons/search.gif" alt="Search" class="searchButton"></a>
            . . .
            . . .
<img src="/images/display/skylines/skylineBlue.jpg" alt="Fashion Institue of Technology Skyline" class="siteBanner" id="siteBanner"></div>
    <a href="/index.asp"><img src="/images/display/general/logo.gif" alt="logo" class="siteLogo"></a>
When doing "stand alone" test (in same folder), <link type="text/css" href="/styles.css" rel="StyleSheet" /> did not work, but href="styles.css" did.