SharePoint content migration is export/import model designed to migrate content from one SharePoint environment to another.

SharePoint content migration is designed on an export/import model. That is, you first export site data, dependencies, and site structure into data files that are rolled up into a content migration package (or multiple packages). Then, the content migration package is imported at the destination, its contents unpacked, and the data, dependencies, and structure are reconstituted on the migration target.

Questions having the tag regards all aspects of migration of content from one SharePoint environment to another.

Reference: Content Migration