For some reason, I have a difficult time finding the brief descriptions of the nine update classifications that you can use to filter the updates you get from Microsoft Updates, so I thought I’d list them here. The source is Microsoft’s “Using the WSUS 3.0 SP2 Configuration Wizard” TechNet article:
Critical Updates: Broadly released fixes for specific problems addressing critical, non-security related bugs.
Definition Updates: Updates to virus or other definition files.
Drivers: Software components designed to support new hardware.
Feature Packs: New feature releases, usually rolled into products at the next release.
Security Updates: Broadly released fixes for specific products, addressing security issues.
Service Packs: Cumulative sets of all hotfixes, security updates, critical updates, and updates created since the release of the product. Service packs might also contain a limited number of customer-requested design changes or features.
Tools: Utilities or features that aid in accomplishing a task or set of tasks.
Update Rollups: Cumulative sets of hotfixes, security updates, critical updates, and updates packaged together for easy deployment. A rollup generally targets a specific area, such as security, or a specific component, such as Internet Information Services (IIS).
Updates: Broadly released fixes for specific problems addressing non-critical, non-security related bugs.