The backups that we take in Smart-1 Cloud every 12 hours are full snapshots of the entire state of your tenant. That means that when TAC perform a restore, it restores everything to the previous state.
This option is important for drastic disaster scenarios (which thankfully are very rare).
As a customer, you also have "less extreme" options to restore to previous configuration if something went wrong, or there is a misconfiguration that you are having trouble tracking down. This is called "Revert to Revision".
The management stores each published session as a revision, which you can see and even compare in the "Settings => Revisions" page. If you right click a specific revision, you can choose to revert back to that revision.
This operation happens within the application, so it is aware of the types of changes done, and can make informed decisions on things that should not be reverted. For example, all policies and objects will be reverted, but if you re-initialized a SIC certificate, that would not be reverted, since the gateway obviously relies on the new SIC.
You can perform the revert to revision action from the UI, or if you prefer, via API.
If you have other cases for backup & restore, or require other granular options, I'd be glad to get more info. You (or others) are welcome to share on this post.