Quick question --- I have replaced an old outdated site (not sure what platform was used to build it) with a new website using my Xara. So far I have desktop and mobile variant and will be adding an ipad variant. When working from Webmaster I noticed an html and htm link to the contact page and of course the older contact page had a "not found code" as it no longer exist.

Just trying to understand htm vs html I looked at my Xara files and realize that Xara only exports htm files. I thought that I had once noticed htm AND html files being uploaded (so I just thought html was the mobile version). Now I am only seeing htm files. Can you please explain the difference and if I did, at some point possibly have both file types or just possibly remembering it wrong.