URL rewriting allows you to obtain shorter URLs by removing the "?q=" part from URLs. In other words, instead of having URLs like this:
http://localhost/?q=album/3-nature
URL rewriting produces the following result:
http://localhost/album/3-nature
URL rewriting only applies to the gallery, not to the administration interface.
This option lets you be notified on the dashboard when a new version of iGalerie is available.