Microsoft Knowledge Base Article 308193 contains the following summary:
You can use the Internet Information Services (IIS) snap-in to configure settings for the WWW and FTP services at the server, individual site, folder, or file levels. When you configure properties at the server level, these values are inherited, and become the default settings for all Web or FTP sites on the server. This article describes how to set the following default properties on an IIS server:
|•||Master properties for the WWW and FTP Services|
|•||Multipurpose Internet Mail Extensions (MIME) Mapping|
|•||Microsoft FrontPage 2000 Server Extensions|
These settings can also be modified at the individual site, folder, or file levels. Note that in most cases, properties that are set at the individual site, folder or file levels override the server level settings.