Configuration backup contains only the system configuration state. It is designed to require little storage and restored quickly.
Create a snapshot of the current system configuration state and save it.
Upload an archive.
Every day a scheduled task adds a snapshot to the list if the configuration has been changed in the last day. The Automatic backups to keep slider sets how many scheduled backups to keep.
Restore the configuration backup item. If the option Download modules automatically is checked, additional modules are downloaded and installed automatically.