Quick-Fix Engineering (QFE)
The QFE is a Microsoft term for the delivery of individual service updates to its operating systems and application programs. Formerly called a hotfix, QFE can be used to describe both the method of delivering and applying a patch or fix, and also to refer to any individual fix.
General Distribution (GDR)
A GDR is typically associated with a critical patch release the product groups feels should be provided to and installed by the whole customer base. GDRs are often associated with security releases, or other critical fixes needed to mitigate a problem the majority of customers will experience when using our product.
Cumulative update package (CU)
Multiple cummulative updates are released between Service Packs and contains all of the applicable hot fixes at the time.
Service Packs (SP)
When there are a large enough collection of changes they are gathered together to be released as a service pack. A service pack can also deliver new product features.