Software patches are files used to update the software already installed on a system.
Patches modify or replace the installed files to add new features, fix bugs, or add support for new hardware. Unlike setup files, which contain all the files needed to run the software, most patches only contain the files that have changed from the previous version. Because of this, patches offer a secure way to update your software. Users must already have a previous version of your software installed in order to make use of a patch. Such open access to service releases makes it easier for your users to keep their software up to date.