When you are testing a web application in visual studio using IIS Express, you'll be able to add a reference to a script file like this (inside an ASPX file):
<head>
<script src="/Javascript/jquery-2.1.1.min.js" type="text/javascript" charset="utf-8"></script>
</head>
However, when you are deploying the exact same application on an standard IIS server (using a web deployment package), you'll get an missing error 404 because the browser won't be able to resolve the url.
To fix it, I could simply remove the slash from the path:
<script src="Javascript/jquery-2.1.1.min.js" type="text/javascript" charset="utf-8"></script>
However, this question ain't about how to fix the link since this question has been asked and answered many time. What I would like to understand is why does IIS Express handle those url correctly while IIS Express ain't able to? Is it question of security (ex: browser has access to you local file while working on your own computer which ain't the case on remote server) or is it a matter of settings the doesn't get exported in the web package?