Update Definitions

Software updates have a variety of names, depending on the issues they address, how they are distributed, and other factors. This chart shows Microsoft’s definitions for commonly used terms, and other characteristics of particular updates.

Not shown in this chart is the update per se (rather than the general term), which fixes noncritical, nonsecurity bugs (and which otherwise has the same attributes as a critical update), and the update rollup, which is a tested, cumulative set of hotfixes, security updates, critical updates, and updates packaged together for easy deployment.

This chart is based on Microsoft’s standard terminology for software updates found at support.microsoft.com/?kbid=824684. (For more information on Mainstream, Extended, and Online Self-Help support phases, see “Support Life-Cycle Phases“.)

	Security Update	Critical Update	Hotfix	Service Pack	Feature Pack
Description	Fixes a product-specific, security-related vulnerability