debian mentors/ glossary/ Debian Version
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Debian Version

The Debian version (or revision) of a package is part of a versioning scheme that is independent of the ?UpstreamVersion of a package. It is used to distinguish versions of a package that use the same ?UpstreamVersion of a package. There are various conventions about these numbers, and some tools behave differently depending on the Debian version of the package they are acting upon.

This doesn't apply for Native packages.

The Debian version of a package is the string after the last - in the version number. If there is no - then the package is a Native package.