versions

A version is a specific state of a project, artifact, or document that is identified by a version number or label. Versions are used to distinguish changes over time and to enable tracking, reproduction, and compatibility decisions. They can apply to software, data schemas, documents, standards, and hardware revisions.

Versioning schemes vary. Common approaches include semantic versioning (SemVer), which uses major.minor.patch numbers; calendar versioning (CalVer), which encodes dates; and simple incremental schemes. Some ecosystems apply additional pre-release or build metadata such as -alpha, -beta, or -rc. In many cases, a repository or release management process assigns version numbers at milestones or releases.

In software, version numbers communicate compatibility guarantees. A major version bump signals breaking changes, a minor version adds features or improvements while remaining backward compatible, and a patch level delivers bug fixes. Developers may maintain a changelog describing changes per version. Dependencies may specify version constraints to ensure compatible combinations.

Version control systems (VCS) such as Git, SVN, or Mercurial manage changes over time and support workflows for releases, tags, and branches. A version is often associated with a tag or a release artifact. Version history enables auditing, rollback, and reproducibility of builds or experiments.

Beyond software, versions track documents, standards (such as RFCs), data schemas, and hardware revisions to provide provenance, citability, and change tracking. Effective versioning relies on clear rules, documentation, and discipline to avoid ambiguity and dependency conflicts.