Yes, although it is optional. URL mapping allows portal administrators to create a different URL and map it to portal pages.
On providing a directory path for a file system collection, URL mapping can be optionally set for each directory.
For example, C:\testfolder can be mapped to http://www.examplesite.com so that even though SearchBlox indexes the content from the file system when a user clicks on the search result, the web document is served from the webserver. The child path would be automatically mapped to the URL.