Deploy a Semantic Model Bundle
If you’re deploying the semantic extensions bundle or the composite bundle, you can either merge or replace the sandbox content and sandbox security in the target environment.
When you replace, you delete the existing semantic model extensions in the target environment and migrate the latest bundle. You must confirm the semantic model replacement to prevent unintended content loss. The merge option is helpful when you've deleted items in your source instance and want those deletions to be applied to the target instance. The default, Merge Sandbox Content, combines the changes from your source sandbox instance with the existing content on the target system.

