Preview, then build
Preview is used to verify how templates, content, and modules will appear on the public page. A preview does not create a release version and does not change live content.
Release versions are immutable
A build captures the currently published pages, assets, and site configuration as a fixed snapshot. This ensures the same version yields consistent results across different environments.
Use a new version to deliver updates
When content needs updating, edit the draft and preview again. After confirming, create a new build and release version; existing versions are not overwritten, which makes auditing and rollback easier.