The local mirror method will process every file in the mirror directories. You start pointing the Builder at the local copy of the web site's root file (typically, index.html). The builder will process all of the files in that directory, and all of its subdirectories. If you build the index with the site map option enabled, any pages not found by crawling links (i.e., they are found only by doing a directory listing) will be contained in a special "Unlinked Pages" folder. This may be helpful to you in finding pages that normal users cannot access by following links from other pages.
Because the Builder operates directly on files, rather than through the HTTP protocol, this is typically a much quicker process than accessing the web site directly. This process is typically available only to the owner of the web site, and works for relatively simple web sites which do not make use of redirects, CGI, server-side includes, in-line servlets, active server pages, and other advanced web site features.
Normally, an index created with this method stores "absolute" addresses. This means that the address for a page is precise, including the host and full path to the page. This could be undesirable in some circumstances:
SiteSurfer addresses this problem by letting you build a "relative" index, by using an address of '.' (a single period) in conjunction with the local mirror and local server methods. When the resultant index is loaded by the SiteSurfer applet, it will resolve the address relative to the directory containing the SiteSurfer applet's HTML file.
There is more information about other build methods.