When changing page names, or, for instance, swapping a site from a static site to a wordpress site, you will want to re-direct any traffic that links to your “old” pages to you “new” pages. You will also want to take the page in question ranking in the search engines across to the new page. This is achieved by a 301 Redirect.

Heres a handy article that explains how to do a 301 Page Redirect