A version control system (VCS) tracks changes to files over time and allows you to restore any previous state. Git is the most widely used VCS. In an ISMS, version control supports traceability of changes to code, configurations, and documents. Combined with branch protection rules and code reviews, it forms the foundation for secure software development per ISO 27001 Annex A.8.25. Even ISMS documents themselves benefit from version control to maintain a complete change history.