Now it goes something like this... 1) I have a simple html website all the pages are cached now, but due to some issues I had to convert those pages to .php extension. Now if my php version also gets cached will I be facing duplicacy issues in search engines like Google and bing? 2) The other question is that if I redesign a website or transfer it to the other domain (urls remains as it is, I might change the locations of the links placed on my webpage), will the PR of my website get affected? Please answer this only if you have faced this issue !!
PalmGEO, Please look over the fact that I am new here, I have been on numerous forums for years, without signing up and have worked on SEO for huge retailers. Anyway to answer your question, all I can say is two things 1. No you won't face duplicacy issues! If you are still worried however, then on the new .php versions of the pages you can specify the canonical url to be the old .html pages. What this does is tell Google that your new .php page should be treated as the old .html, for link juice, page rank and all the other goodies it has Google "Matt Cutts Canonical URL" for more info ;-) 2.Your site may fall off the SERPS for a short time, however assuming the new domain url is appropriate for the keywords you are ranking for, it will reappear when Google crawls it again. Your PR is affected by the number of quality sites you have linking to you. If you change your domain, then your current back links will naturally be linking to the old domain. Are you making a new keyword rich domain for your site? Otherwise I suggest setting up permanent redirects to avoid losing some google juice.