The Java ES release model is based on a set of release levels that define the characteristics of individual Java ES component releases:
Major release. The purpose of a major release is to introduce or change significant software functionality and architectural features. As such, it can introduce incompatibilities with previous versions, and operating system support may be dropped. As a result, users may be required to take specific actions in order for their applications to integrate with a major release. As part of upgrading to a new major release, users might have to perform migrations, redeployments, and possibly redesign their solutions to utilize new features or respond to the removal of old features.
Minor release. The purpose of a minor release is to introduce new, non-interfering features without introducing incompatibilities. New prerequisites or dependencies can be established and previous features can be deprecated in a minor release. As compared to upgrading to a major release, users might have to perform migrations and redeployments, but a redesign of their existing solution should not be necessary.
Update release. The purpose of an update release is to provide fixes to an existing component implementation so that it more accurately implements a prior release's functional specification. The update release provides for the delivery of bug fixes and a constrained set of feature enhancements such that the release remains suitable for adoption by the majority of existing users. When compared to a major or minor release an update release contains fewer, smaller and/or lower risk features. Other than in rare exceptions, an update release is 100% backwardly compatible with the prior release. Upgrading to an update release from the prior release should require minimal planning and investment.
Point-fix release. The purpose of a point-fix release is to address critical customer issues quickly. Like an update release, it supports existing users, but is generally more limited or focused, typically containing only a few bug fixes. Feature enhancements or new feature additions are not allowed in a point-fix release. Upgrading to a point-fix release from the prior release should be simple an low risk.