Sometimes you, or someone from technical support, will need to view the text of a template file in its raw form, without being processed by WebCatalog. Usually this is so you can see the WebDNA commands rather than seeing the final resulting HTML those WebDNA commands generate. WebCatalog normally intercepts URLs that lead to template files, and makes it impossible to to 'view the source' of a WebDNA template.
The Raw command is provided for sites that use Suffix Mapping to automatically process all files that end in a particular extension. In this scenario, it is impossible to link to the file directly to see the raw contents of the file. While this is good because it does not allow the outside world to see the contents of your pages, it can make site development difficult if you are debugging a particular page remotely. The Raw command should be protected with the Admin password so it is not available to everyone accessing your site.