Hi lheath,
SharePoint Online does back up data for customers. Data protection services are provided to prevent the loss of SharePoint Online data. Backups are performed every 12 hours and retained for 14 days:
For more information, you can refer to:
Microsoft SharePoint Online for Enterprises Service Description
Users can also manually back up their SharePoint Online data by downloading the documents, saving the sites as templates, etc.
Thanks,
Cherry Wang