You will usually be adding Liquibase Business to existing pipelines of databases, so you need a method to tell Liquibase Business when changes within the Changelog are already in a given database. This is accomplished via the ChangelogSync command via the GUI or CLI.
The changelogSync command is typically used when you want to baseline a new database environment. For example, you can use the changeLogSync command to mark a change as executed if the object associated with the change was created manually on the database. By marking the changeset as executed, it prevents the next Liquibase update from failing as it tries to create an object that already exists.
Here is a video that explains using ChangelogSync: