wheel - 1:34 pm on Nov 28, 2011 (gmt 0)
I think he's talking about being able to define URLS's so that you don't lose your site structure.
i.e. if your web page is currently exampledotcom/widgets/redwidgets.html, then you want to make sure that your new software keeps that same url, and doesn't rename it to something else.
That way all google sees is a change of template, not a whole new site with structure to crawl, pages to re-rank, links to recalculate, etc.