Windows Server Update Services (WSUS) Classifications :

The following table lists examples of update classifications:

Update Classifications	Description
Connectors	Software components designed to support connection between software.
Critical updates	Broadly released fixes for specific problems addressing critical, non-security related bugs.
Development kits	Software to aid the writing of new applications that usually includes a visual builder, an editor, and a compiler.
Drivers	Software components designed to support new hardware.
Feature packs	New product functionality usually included in the next full product release.
Guidance	Scripts, sample code, and technical guidance designed to help in the deployment and use of a product or technology.
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 set 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.