Note: This article assumes you have read About Database Collections.
With Velo, you can manage your site history in the same way you would manage the history of a site that doesn't use Velo.
When restoring an older version of your site, your pages, code, hooks, routers, schemas, and permissions are all restored to their state from the older version. However, your data—in both the Sandbox and Live databases—is not restored. In other words, you cannot retrieve deleted data by reverting to an older version of your site.
While your data does not change when restoring an older version of your site, the schema reverts to the older version's schema. This means that a field that exists in the schema in the newer version may not exist in the schema in the older version. You can add the field to the schema in the older version after reverting. The data itself is maintained. It will appear once the field is added to the schema.