Joomla! Documentation™

A patch in Joomla! is a bunch of bugfixes, and might or might not include security issues. The patch announcement will always tell if a patch has fixed security issues. A patch is a minor upgrade. From Joomla! 1.0.0 to Joomla! 1.0.7 is considered a patch. Going from Joomla! 1.0,x to Joomla! 1.5 will be a major upgrade and should be treated differently.