A software update or patch is any update or hot fix that is used to improve or fix a software product. A software bulletin is a bundle of software updates that are released together.
Patch Management Solution for Windows uses targeted deployments. Updates are not deployed to a computer unless that computer specifically needs that software update. If a managed computer meets the prerequisites of a software update, it falls into a targeted filter. The prerequisites are matched against the data that is sent to Notification Server by the software update plug-in: for example, the Internet Explorer and operating system versions. Software updates are then installed according to the software vendor specifications. For example, if the update requires a restart, then the computer is restarted after the update is installed. Service Packs are installed before other software updates.
When a software update has been superseded and rendered obsolete by another update or updates, the later update is installed.
The software vendor assigns severity levels to software updates, but you can also create a custom severity level.
You must ensure that each software update works correctly in your environment before deploying it. Symantec recommends that you first distribute any required software update in a test environment before deploying it to your production environment.