Feature Pack
Definition: A feature pack is new product functionality that is first
distributed outside the context of a product release and that is
typically included in the next full product release.
Hotfix
Definition: A hotfix is a single, cumulative package that includes one
or more files that are used to address a problem in a product and are
cumulative at the binary and file level. A hotfix addresses a specific
customer situation and may not be distributed outside the customer's
organization.
Additional Information: Hotfixes are distributed by Microsoft Product
Support Services. Customers may not redistribute hotfixes without
written, legal consent from Microsoft.
Security Update
Definition: A security update is a broadly released fix for a product-
specific, security-related vulnerability. Security vulnerabilities are
rated based on their severity. The severity rating is indicated in the
Microsoft security bulletin as critical, important, moderate, or low.
Service Pack
Definition: A service pack is a tested, cumulative set of all
hotfixes, security updates, critical updates, and updates. Service
packs may also contain additional fixes for problems that are found
internally since the release of the product and a limited number of
customer-requested design changes or features.
Software Update
Definition: A software update is any update, update rollup, service
pack, feature pack, critical update, security update, or hotfix that
is used to improve or to fix a software product that is released by
Microsoft Corporation.
Update
Definition: An update is a broadly released fix for a specific
problem. An update addresses a non-critical, non-security-related
bug.
Update Rollup
Definition: An update rollup is a tested, cumulative set of hotfixes,
security updates, critical updates, and updates that are packaged
together for easy deployment. A rollup generally targets a specific
area, such as security, or a component of a product, such as Internet
Information Services (IIS).