Editing Software versioning (section)

=== In software engineering ===
Version numbers are used in practical terms by the consumer, or [[consumer|client]], to identify or compare their copy of the software product against another copy, such as the newest version released by the developer. For the programmer or company, versioning is often used on a revision-by-revision basis, where individual parts of the software are compared and contrasted with newer or older revisions of those same parts, often in a collaborative [[version control system]].

In the 21st century, more programmers started to use a formalized version policy, such as the semantic versioning policy.<ref name="semver" /> The purpose of such policies is to make it easier for other programmers to know when code changes are likely to break things they have written. Such policies are especially important for [[software libraries]] and [[software framework|frameworks]], but may also be very useful for command-line applications (which may be called from other applications) and for other applications (which may be scripted and/or extended by third parties).

Versioning is also a required practice to enable many schemes of patching and upgrading software, especially to automatically decide what and where to upgrade to.